diff --git a/app/controllers/transactions_controller.rb b/app/controllers/transactions_controller.rb
index 2036bd168..aec15157b 100644
--- a/app/controllers/transactions_controller.rb
+++ b/app/controllers/transactions_controller.rb
@@ -116,6 +116,49 @@ class TransactionsController < ApplicationController
     end
   end
 
+  def mark_as_recurring
+    transaction = Current.family.transactions.includes(entry: :account).find(params[:id])
+
+    # Check if a recurring transaction already exists for this pattern
+    existing = Current.family.recurring_transactions.find_by(
+      merchant_id: transaction.merchant_id,
+      name: transaction.merchant_id.present? ? nil : transaction.entry.name,
+      currency: transaction.entry.currency,
+      manual: true
+    )
+
+    if existing
+      flash[:alert] = t("recurring_transactions.already_exists")
+      redirect_back_or_to transactions_path
+      return
+    end
+
+    begin
+      recurring_transaction = RecurringTransaction.create_from_transaction(transaction)
+
+      respond_to do |format|
+        format.html do
+          flash[:notice] = t("recurring_transactions.marked_as_recurring")
+          redirect_back_or_to transactions_path
+        end
+      end
+    rescue ActiveRecord::RecordInvalid => e
+      respond_to do |format|
+        format.html do
+          flash[:alert] = t("recurring_transactions.creation_failed")
+          redirect_back_or_to transactions_path
+        end
+      end
+    rescue StandardError => e
+      respond_to do |format|
+        format.html do
+          flash[:alert] = t("recurring_transactions.unexpected_error")
+          redirect_back_or_to transactions_path
+        end
+      end
+    end
+  end
+
   private
     def per_page
       params[:per_page].to_i.positive? ? params[:per_page].to_i : 20
diff --git a/app/models/recurring_transaction.rb b/app/models/recurring_transaction.rb
index b97ad858b..069440725 100644
--- a/app/models/recurring_transaction.rb
+++ b/app/models/recurring_transaction.rb
@@ -5,6 +5,9 @@ class RecurringTransaction < ApplicationRecord
   belongs_to :merchant, optional: true
 
   monetize :amount
+  monetize :expected_amount_min, allow_nil: true
+  monetize :expected_amount_max, allow_nil: true
+  monetize :expected_amount_avg, allow_nil: true
 
   enum :status, { active: "active", inactive: "inactive" }
 
@@ -12,6 +15,7 @@ class RecurringTransaction < ApplicationRecord
   validates :currency, presence: true
   validates :expected_day_of_month, presence: true, numericality: { greater_than: 0, less_than_or_equal_to: 31 }
   validate :merchant_or_name_present
+  validate :amount_variance_consistency
 
   def merchant_or_name_present
     if merchant_id.blank? && name.blank?
@@ -19,6 +23,16 @@ class RecurringTransaction < ApplicationRecord
     end
   end
 
+  def amount_variance_consistency
+    return unless manual?
+
+    if expected_amount_min.present? && expected_amount_max.present?
+      if expected_amount_min > expected_amount_max
+        errors.add(:expected_amount_min, "cannot be greater than expected_amount_max")
+      end
+    end
+  end
+
   scope :for_family, ->(family) { where(family: family) }
   scope :expected_soon, -> { active.where("next_expected_date <= ?", 1.month.from_now) }
 
@@ -31,17 +45,147 @@ class RecurringTransaction < ApplicationRecord
     Cleaner.new(family).cleanup_stale_transactions
   end
 
-  # Find matching transactions for this recurring pattern
-  def matching_transactions
+  # Create a manual recurring transaction from an existing transaction
+  # Automatically calculates amount variance from past 6 months of matching transactions
+  def self.create_from_transaction(transaction, date_variance: 2)
+    entry = transaction.entry
+    family = entry.account.family
+    expected_day = entry.date.day
+
+    # Find matching transactions from the past 6 months
+    matching_amounts = find_matching_transaction_amounts(
+      family: family,
+      merchant_id: transaction.merchant_id,
+      name: transaction.merchant_id.present? ? nil : entry.name,
+      currency: entry.currency,
+      expected_day: expected_day,
+      lookback_months: 6
+    )
+
+    # Calculate amount variance from historical data
+    expected_min = expected_max = expected_avg = nil
+    if matching_amounts.size > 1
+      # Multiple transactions found - calculate variance
+      expected_min = matching_amounts.min
+      expected_max = matching_amounts.max
+      expected_avg = matching_amounts.sum / matching_amounts.size
+    elsif matching_amounts.size == 1
+      # Single transaction - no variance yet
+      amount = matching_amounts.first
+      expected_min = amount
+      expected_max = amount
+      expected_avg = amount
+    end
+
+    # Calculate next expected date relative to today, not the transaction date
+    next_expected = calculate_next_expected_date_from_today(expected_day)
+
+    create!(
+      family: family,
+      merchant_id: transaction.merchant_id,
+      name: transaction.merchant_id.present? ? nil : entry.name,
+      amount: entry.amount,
+      currency: entry.currency,
+      expected_day_of_month: expected_day,
+      last_occurrence_date: entry.date,
+      next_expected_date: next_expected,
+      status: "active",
+      occurrence_count: matching_amounts.size,
+      manual: true,
+      expected_amount_min: expected_min,
+      expected_amount_max: expected_max,
+      expected_amount_avg: expected_avg
+    )
+  end
+
+  # Find matching transaction entries for variance calculation
+  def self.find_matching_transaction_entries(family:, merchant_id:, name:, currency:, expected_day:, lookback_months: 6)
+    lookback_date = lookback_months.months.ago.to_date
+
     entries = family.entries
       .where(entryable_type: "Transaction")
       .where(currency: currency)
-      .where("entries.amount = ?", amount)
+      .where("entries.date >= ?", lookback_date)
       .where("EXTRACT(DAY FROM entries.date) BETWEEN ? AND ?",
-             [ expected_day_of_month - 2, 1 ].max,
-             [ expected_day_of_month + 2, 31 ].min)
+             [ expected_day - 2, 1 ].max,
+             [ expected_day + 2, 31 ].min)
       .order(date: :desc)
 
+    # Filter by merchant or name
+    if merchant_id.present?
+      # Join with transactions table to filter by merchant_id in SQL (avoids N+1)
+      entries
+        .joins("INNER JOIN transactions ON transactions.id = entries.entryable_id")
+        .where(transactions: { merchant_id: merchant_id })
+        .to_a
+    else
+      entries.where(name: name).to_a
+    end
+  end
+
+  # Find matching transaction amounts for variance calculation
+  def self.find_matching_transaction_amounts(family:, merchant_id:, name:, currency:, expected_day:, lookback_months: 6)
+    matching_entries = find_matching_transaction_entries(
+      family: family,
+      merchant_id: merchant_id,
+      name: name,
+      currency: currency,
+      expected_day: expected_day,
+      lookback_months: lookback_months
+    )
+
+    matching_entries.map(&:amount)
+  end
+
+  # Calculate next expected date from today
+  def self.calculate_next_expected_date_from_today(expected_day)
+    today = Date.current
+
+    # Try this month first
+    begin
+      this_month_date = Date.new(today.year, today.month, expected_day)
+      return this_month_date if this_month_date > today
+    rescue ArgumentError
+      # Day doesn't exist in this month (e.g., 31st in February)
+    end
+
+    # Otherwise use next month
+    calculate_next_expected_date_for(today, expected_day)
+  end
+
+  def self.calculate_next_expected_date_for(from_date, expected_day)
+    next_month = from_date.next_month
+    begin
+      Date.new(next_month.year, next_month.month, expected_day)
+    rescue ArgumentError
+      next_month.end_of_month
+    end
+  end
+
+  # Find matching transactions for this recurring pattern
+  def matching_transactions
+    # For manual recurring with amount variance, match within range
+    # For automatic recurring, match exact amount
+    entries = if manual? && has_amount_variance?
+      family.entries
+        .where(entryable_type: "Transaction")
+        .where(currency: currency)
+        .where("entries.amount BETWEEN ? AND ?", expected_amount_min, expected_amount_max)
+        .where("EXTRACT(DAY FROM entries.date) BETWEEN ? AND ?",
+               [ expected_day_of_month - 2, 1 ].max,
+               [ expected_day_of_month + 2, 31 ].min)
+        .order(date: :desc)
+    else
+      family.entries
+        .where(entryable_type: "Transaction")
+        .where(currency: currency)
+        .where("entries.amount = ?", amount)
+        .where("EXTRACT(DAY FROM entries.date) BETWEEN ? AND ?",
+               [ expected_day_of_month - 2, 1 ].max,
+               [ expected_day_of_month + 2, 31 ].min)
+        .order(date: :desc)
+    end
+
     # Filter by merchant or name
     if merchant_id.present?
       # Match by merchant through the entryable (Transaction)
@@ -54,10 +198,17 @@ class RecurringTransaction < ApplicationRecord
     end
   end
 
+  # Check if this recurring transaction has amount variance configured
+  def has_amount_variance?
+    expected_amount_min.present? && expected_amount_max.present?
+  end
+
   # Check if this recurring transaction should be marked inactive
   def should_be_inactive?
     return false if last_occurrence_date.nil?
-    last_occurrence_date < 2.months.ago
+    # Manual recurring transactions have a longer threshold
+    threshold = manual? ? 6.months.ago : 2.months.ago
+    last_occurrence_date < threshold
   end
 
   # Mark as inactive
@@ -71,14 +222,42 @@ class RecurringTransaction < ApplicationRecord
   end
 
   # Update based on a new transaction occurrence
-  def record_occurrence!(transaction_date)
+  def record_occurrence!(transaction_date, transaction_amount = nil)
     self.last_occurrence_date = transaction_date
     self.next_expected_date = calculate_next_expected_date(transaction_date)
+
+    # Update amount variance for manual recurring transactions BEFORE incrementing count
+    if manual? && transaction_amount.present?
+      update_amount_variance(transaction_amount)
+    end
+
     self.occurrence_count += 1
     self.status = "active"
     save!
   end
 
+  # Update amount variance tracking based on a new transaction
+  def update_amount_variance(transaction_amount)
+    # First sample - initialize everything
+    if expected_amount_avg.nil?
+      self.expected_amount_min = transaction_amount
+      self.expected_amount_max = transaction_amount
+      self.expected_amount_avg = transaction_amount
+      return
+    end
+
+    # Update min/max
+    self.expected_amount_min = [ expected_amount_min, transaction_amount ].min if expected_amount_min.present?
+    self.expected_amount_max = [ expected_amount_max, transaction_amount ].max if expected_amount_max.present?
+
+    # Calculate new average using incremental formula
+    # For n samples with average A_n, adding sample x_{n+1} gives:
+    # A_{n+1} = A_n + (x_{n+1} - A_n)/(n+1)
+    # occurrence_count includes the initial occurrence, so subtract 1 to get variance samples recorded
+    n = occurrence_count - 1  # Number of variance samples recorded so far
+    self.expected_amount_avg = expected_amount_avg + ((transaction_amount - expected_amount_avg) / (n + 1))
+  end
+
   # Calculate the next expected date based on the last occurrence
   def calculate_next_expected_date(from_date = last_occurrence_date)
     # Start with next month
@@ -98,14 +277,25 @@ class RecurringTransaction < ApplicationRecord
     return nil unless active?
     return nil unless next_expected_date.future?
 
+    # Use average amount for manual recurring with variance, otherwise use fixed amount
+    display_amount = if manual? && expected_amount_avg.present?
+      expected_amount_avg
+    else
+      amount
+    end
+
     OpenStruct.new(
       date: next_expected_date,
-      amount: amount,
+      amount: display_amount,
       currency: currency,
       merchant: merchant,
       name: merchant.present? ? merchant.name : name,
       recurring: true,
-      projected: true
+      projected: true,
+      amount_min: expected_amount_min,
+      amount_max: expected_amount_max,
+      amount_avg: expected_amount_avg,
+      has_variance: has_amount_variance?
     )
   end
 
diff --git a/app/models/recurring_transaction/cleaner.rb b/app/models/recurring_transaction/cleaner.rb
index ea7091051..4aecbb343 100644
--- a/app/models/recurring_transaction/cleaner.rb
+++ b/app/models/recurring_transaction/cleaner.rb
@@ -6,18 +6,19 @@ class RecurringTransaction
       @family = family
     end
 
-    # Mark recurring transactions as inactive if they haven't occurred in 2+ months
+    # Mark recurring transactions as inactive if they haven't occurred recently
+    # Uses 2 months for automatic recurring, 6 months for manual recurring
     def cleanup_stale_transactions
-      two_months_ago = 2.months.ago.to_date
-
-      stale_transactions = family.recurring_transactions
-        .active
-        .where("last_occurrence_date < ?", two_months_ago)
-
       stale_count = 0
-      stale_transactions.find_each do |recurring_transaction|
+
+      family.recurring_transactions.active.find_each do |recurring_transaction|
+        next unless recurring_transaction.should_be_inactive?
+
+        # Determine threshold based on manual flag
+        threshold = recurring_transaction.manual? ? 6.months.ago.to_date : 2.months.ago.to_date
+
         # Double-check if there are any recent matching transactions
-        recent_matches = recurring_transaction.matching_transactions.select { |entry| entry.date >= two_months_ago }
+        recent_matches = recurring_transaction.matching_transactions.select { |entry| entry.date >= threshold }
 
         if recent_matches.empty?
           recurring_transaction.mark_inactive!
@@ -29,11 +30,13 @@ class RecurringTransaction
     end
 
     # Remove inactive recurring transactions that have been inactive for 6+ months
+    # Manual recurring transactions are never automatically deleted
     def remove_old_inactive_transactions
       six_months_ago = 6.months.ago
 
       family.recurring_transactions
         .inactive
+        .where(manual: false)
         .where("updated_at < ?", six_months_ago)
         .destroy_all
     end
diff --git a/app/models/recurring_transaction/identifier.rb b/app/models/recurring_transaction/identifier.rb
index 6d6374b53..33fc0d9bf 100644
--- a/app/models/recurring_transaction/identifier.rb
+++ b/app/models/recurring_transaction/identifier.rb
@@ -84,6 +84,13 @@ class RecurringTransaction
 
         recurring_transaction = family.recurring_transactions.find_or_initialize_by(find_conditions)
 
+        # Handle manual recurring transactions specially
+        if recurring_transaction.persisted? && recurring_transaction.manual?
+          # Update variance for manual recurring transactions
+          update_manual_recurring_variance(recurring_transaction, pattern)
+          next
+        end
+
         # Set the name or merchant_id on new records
         if recurring_transaction.new_record?
           if pattern[:merchant_id].present?
@@ -91,6 +98,8 @@ class RecurringTransaction
           else
             recurring_transaction.name = pattern[:name]
           end
+          # New auto-detected recurring transactions are not manual
+          recurring_transaction.manual = false
         end
 
         recurring_transaction.assign_attributes(
@@ -104,9 +113,74 @@ class RecurringTransaction
         recurring_transaction.save!
       end
 
+      # Also check for manual recurring transactions that might need variance updates
+      update_manual_recurring_transactions(three_months_ago)
+
       recurring_patterns.size
     end
 
+    # Update variance for existing manual recurring transactions
+    def update_manual_recurring_transactions(since_date)
+      family.recurring_transactions.where(manual: true, status: "active").find_each do |recurring|
+        # Find matching transactions in the recent period
+        matching_entries = RecurringTransaction.find_matching_transaction_entries(
+          family: family,
+          merchant_id: recurring.merchant_id,
+          name: recurring.name,
+          currency: recurring.currency,
+          expected_day: recurring.expected_day_of_month,
+          lookback_months: 6
+        )
+
+        next if matching_entries.empty?
+
+        # Extract amounts and dates from all matching entries
+        matching_amounts = matching_entries.map(&:amount)
+        last_entry = matching_entries.max_by(&:date)
+
+        # Recalculate variance from all occurrences (including identical amounts)
+        recurring.update!(
+          expected_amount_min: matching_amounts.min,
+          expected_amount_max: matching_amounts.max,
+          expected_amount_avg: matching_amounts.sum / matching_amounts.size,
+          occurrence_count: matching_amounts.size,
+          last_occurrence_date: last_entry.date,
+          next_expected_date: calculate_next_expected_date(last_entry.date, recurring.expected_day_of_month)
+        )
+      end
+    end
+
+    # Update variance for a manual recurring transaction when pattern is found
+    def update_manual_recurring_variance(recurring_transaction, pattern)
+      # Check if this transaction's date is more recent
+      if pattern[:last_occurrence_date] > recurring_transaction.last_occurrence_date
+        # Find all matching transactions to recalculate variance
+        matching_entries = RecurringTransaction.find_matching_transaction_entries(
+          family: family,
+          merchant_id: recurring_transaction.merchant_id,
+          name: recurring_transaction.name,
+          currency: recurring_transaction.currency,
+          expected_day: recurring_transaction.expected_day_of_month,
+          lookback_months: 6
+        )
+
+        # Update if we have any matching transactions
+        if matching_entries.any?
+          matching_amounts = matching_entries.map(&:amount)
+
+          recurring_transaction.update!(
+            expected_amount_min: matching_amounts.min,
+            expected_amount_max: matching_amounts.max,
+            expected_amount_avg: matching_amounts.sum / matching_amounts.size,
+            occurrence_count: matching_amounts.size,
+            last_occurrence_date: pattern[:last_occurrence_date],
+            next_expected_date: calculate_next_expected_date(pattern[:last_occurrence_date], recurring_transaction.expected_day_of_month),
+            status: "active"
+          )
+        end
+      end
+    end
+
     private
       # Check if days cluster together (within ~5 days variance)
       # Uses circular distance to handle month-boundary wrapping (e.g., 28, 29, 30, 31, 1, 2)
diff --git a/app/views/recurring_transactions/_projected_transaction.html.erb b/app/views/recurring_transactions/_projected_transaction.html.erb
index 050fd72fe..201161f4c 100644
--- a/app/views/recurring_transactions/_projected_transaction.html.erb
+++ b/app/views/recurring_transactions/_projected_transaction.html.erb
@@ -54,6 +54,7 @@
   </div>
 
   <div class="col-span-2 ml-auto text-right">
-    <%= content_tag :p, format_money(-recurring_transaction.amount_money), class: ["font-medium", recurring_transaction.amount.negative? ? "text-success" : "text-subdued"] %>
+    <% display_amount = recurring_transaction.manual? && recurring_transaction.expected_amount_avg.present? ? recurring_transaction.expected_amount_avg : recurring_transaction.amount %>
+    <%= content_tag :p, format_money(-Money.new(display_amount, recurring_transaction.currency)), class: ["font-medium", display_amount.negative? ? "text-success" : "text-subdued"] %>
   </div>
 </div>
diff --git a/app/views/recurring_transactions/index.html.erb b/app/views/recurring_transactions/index.html.erb
index 4f1925884..1917a9624 100644
--- a/app/views/recurring_transactions/index.html.erb
+++ b/app/views/recurring_transactions/index.html.erb
@@ -100,10 +100,22 @@
                       ) %>
                       <span class="text-primary font-medium"><%= recurring_transaction.name %></span>
                     <% end %>
+                    <% if recurring_transaction.manual? %>
+                      <span class="inline-flex items-center px-2 py-0.5 rounded text-xs font-medium bg-blue-tint-10 text-link">
+                        <%= t("recurring_transactions.badges.manual") %>
+                      </span>
+                    <% end %>
                   </div>
                 </td>
                 <td class="py-3 px-2 text-sm font-medium <%= recurring_transaction.amount.negative? ? "text-success" : "text-primary" %>">
-                  <%= format_money(-recurring_transaction.amount_money) %>
+                  <% if recurring_transaction.manual? && recurring_transaction.has_amount_variance? %>
+                    <div class="inline-flex items-center gap-1 cursor-help group" title="<%= t('recurring_transactions.amount_range', min: format_money(-recurring_transaction.expected_amount_min_money), max: format_money(-recurring_transaction.expected_amount_max_money)) %>">
+                      <span class="text-xs text-secondary group-hover:text-primary transition-colors">~</span>
+                      <span class="border-b border-dashed border-subdued group-hover:border-primary transition-colors"><%= format_money(-recurring_transaction.expected_amount_avg_money) %></span>
+                    </div>
+                  <% else %>
+                    <%= format_money(-recurring_transaction.amount_money) %>
+                  <% end %>
                 </td>
                 <td class="py-3 px-2 text-sm text-secondary">
                   <%= t("recurring_transactions.day_of_month", day: recurring_transaction.expected_day_of_month) %>
diff --git a/app/views/transactions/show.html.erb b/app/views/transactions/show.html.erb
index 770f1482b..7cac8550f 100644
--- a/app/views/transactions/show.html.erb
+++ b/app/views/transactions/show.html.erb
@@ -150,6 +150,23 @@
           ) %>
         </div>
 
+        <!-- Mark as Recurring Form -->
+        <div class="flex items-center justify-between gap-2 p-3">
+          <div class="text-sm space-y-1">
+            <h4 class="text-primary"><%= t(".mark_recurring_title") %></h4>
+            <p class="text-secondary"><%= t(".mark_recurring_subtitle") %></p>
+          </div>
+
+          <%= render DS::Button.new(
+            text: t(".mark_recurring"),
+            variant: "outline",
+            icon: "repeat",
+            href: mark_as_recurring_transaction_path(@entry.transaction),
+            method: :post,
+            frame: "_top"
+          ) %>
+        </div>
+
         <!-- Delete Transaction Form -->
         <div class="flex items-center justify-between gap-2 p-3">
           <div class="text-sm space-y-1">
diff --git a/config/locales/views/recurring_transactions/en.yml b/config/locales/views/recurring_transactions/en.yml
index 421426c45..7541c1f16 100644
--- a/config/locales/views/recurring_transactions/en.yml
+++ b/config/locales/views/recurring_transactions/en.yml
@@ -22,6 +22,11 @@ en:
     marked_active: Recurring transaction marked as active
     deleted: Recurring transaction deleted
     confirm_delete: Are you sure you want to delete this recurring transaction?
+    marked_as_recurring: Transaction marked as recurring
+    already_exists: A manual recurring transaction already exists for this pattern
+    creation_failed: Failed to create recurring transaction. Please check the transaction details and try again.
+    unexpected_error: An unexpected error occurred while creating the recurring transaction
+    amount_range: "Range: %{min} to %{max}"
     empty:
       title: No recurring transactions found
       description: Click "Identify Patterns" to automatically detect recurring transactions from your transaction history.
@@ -36,3 +41,5 @@ en:
     status:
       active: Active
       inactive: Inactive
+    badges:
+      manual: Manual
diff --git a/config/locales/views/transactions/en.yml b/config/locales/views/transactions/en.yml
index 0655145f5..c5362457c 100644
--- a/config/locales/views/transactions/en.yml
+++ b/config/locales/views/transactions/en.yml
@@ -30,6 +30,9 @@ en:
         balances, and cannot be undone.
       delete_title: Delete transaction
       details: Details
+      mark_recurring: Mark as Recurring
+      mark_recurring_subtitle: Track this as a recurring transaction. Amount variance is automatically calculated from past 6 months of similar transactions.
+      mark_recurring_title: Recurring Transaction
       merchant_label: Merchant
       name_label: Name
       nature: Type
diff --git a/config/routes.rb b/config/routes.rb
index 9d327f32f..5087ca0ea 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -153,6 +153,10 @@ Rails.application.routes.draw do
     collection do
       delete :clear_filter
     end
+
+    member do
+      post :mark_as_recurring
+    end
   end
 
   resources :recurring_transactions, only: %i[index destroy] do
diff --git a/db/migrate/20251110143516_add_manual_and_amount_variance_to_recurring_transactions.rb b/db/migrate/20251110143516_add_manual_and_amount_variance_to_recurring_transactions.rb
new file mode 100644
index 000000000..d86e94b22
--- /dev/null
+++ b/db/migrate/20251110143516_add_manual_and_amount_variance_to_recurring_transactions.rb
@@ -0,0 +1,8 @@
+class AddManualAndAmountVarianceToRecurringTransactions < ActiveRecord::Migration[7.2]
+  def change
+    add_column :recurring_transactions, :manual, :boolean, default: false, null: false
+    add_column :recurring_transactions, :expected_amount_min, :decimal, precision: 19, scale: 4
+    add_column :recurring_transactions, :expected_amount_max, :decimal, precision: 19, scale: 4
+    add_column :recurring_transactions, :expected_amount_avg, :decimal, precision: 19, scale: 4
+  end
+end
diff --git a/test/controllers/transactions_controller_test.rb b/test/controllers/transactions_controller_test.rb
index c2cc94b7f..f737ef820 100644
--- a/test/controllers/transactions_controller_test.rb
+++ b/test/controllers/transactions_controller_test.rb
@@ -190,4 +190,97 @@ end
     get transactions_url(q: { categories: [ "Food" ], types: [ "expense" ] })
     assert_response :success
   end
+
+  test "mark_as_recurring creates a manual recurring transaction" do
+    family = families(:empty)
+    sign_in users(:empty)
+    account = family.accounts.create! name: "Test", balance: 0, currency: "USD", accountable: Depository.new
+    merchant = family.merchants.create! name: "Test Merchant"
+    entry = create_transaction(account: account, amount: 100, merchant: merchant)
+    transaction = entry.entryable
+
+    assert_difference "family.recurring_transactions.count", 1 do
+      post mark_as_recurring_transaction_path(transaction)
+    end
+
+    assert_redirected_to transactions_path
+    assert_equal "Transaction marked as recurring", flash[:notice]
+
+    recurring = family.recurring_transactions.last
+    assert_equal true, recurring.manual, "Expected recurring transaction to be manual"
+    assert_equal merchant.id, recurring.merchant_id
+    assert_equal entry.currency, recurring.currency
+    assert_equal entry.date.day, recurring.expected_day_of_month
+  end
+
+  test "mark_as_recurring shows alert if recurring transaction already exists" do
+    family = families(:empty)
+    sign_in users(:empty)
+    account = family.accounts.create! name: "Test", balance: 0, currency: "USD", accountable: Depository.new
+    merchant = family.merchants.create! name: "Test Merchant"
+    entry = create_transaction(account: account, amount: 100, merchant: merchant)
+    transaction = entry.entryable
+
+    # Create existing recurring transaction
+    family.recurring_transactions.create!(
+      merchant: merchant,
+      amount: entry.amount,
+      currency: entry.currency,
+      expected_day_of_month: entry.date.day,
+      last_occurrence_date: entry.date,
+      next_expected_date: 1.month.from_now,
+      status: "active",
+      manual: true,
+      occurrence_count: 1
+    )
+
+    assert_no_difference "RecurringTransaction.count" do
+      post mark_as_recurring_transaction_path(transaction)
+    end
+
+    assert_redirected_to transactions_path
+    assert_equal "A manual recurring transaction already exists for this pattern", flash[:alert]
+  end
+
+  test "mark_as_recurring handles validation errors gracefully" do
+    family = families(:empty)
+    sign_in users(:empty)
+    account = family.accounts.create! name: "Test", balance: 0, currency: "USD", accountable: Depository.new
+    merchant = family.merchants.create! name: "Test Merchant"
+    entry = create_transaction(account: account, amount: 100, merchant: merchant)
+    transaction = entry.entryable
+
+    # Stub create_from_transaction to raise a validation error
+    RecurringTransaction.expects(:create_from_transaction).raises(
+      ActiveRecord::RecordInvalid.new(
+        RecurringTransaction.new.tap { |rt| rt.errors.add(:base, "Test validation error") }
+      )
+    )
+
+    assert_no_difference "RecurringTransaction.count" do
+      post mark_as_recurring_transaction_path(transaction)
+    end
+
+    assert_redirected_to transactions_path
+    assert_equal "Failed to create recurring transaction. Please check the transaction details and try again.", flash[:alert]
+  end
+
+  test "mark_as_recurring handles unexpected errors gracefully" do
+    family = families(:empty)
+    sign_in users(:empty)
+    account = family.accounts.create! name: "Test", balance: 0, currency: "USD", accountable: Depository.new
+    merchant = family.merchants.create! name: "Test Merchant"
+    entry = create_transaction(account: account, amount: 100, merchant: merchant)
+    transaction = entry.entryable
+
+    # Stub create_from_transaction to raise an unexpected error
+    RecurringTransaction.expects(:create_from_transaction).raises(StandardError.new("Unexpected error"))
+
+    assert_no_difference "RecurringTransaction.count" do
+      post mark_as_recurring_transaction_path(transaction)
+    end
+
+    assert_redirected_to transactions_path
+    assert_equal "An unexpected error occurred while creating the recurring transaction", flash[:alert]
+  end
 end
diff --git a/test/models/recurring_transaction_test.rb b/test/models/recurring_transaction_test.rb
index 6ce2065c7..1e920d7cb 100644
--- a/test/models/recurring_transaction_test.rb
+++ b/test/models/recurring_transaction_test.rb
@@ -324,4 +324,283 @@ class RecurringTransactionTest < ActiveSupport::TestCase
     assert name_based.present?
     assert_equal "Monthly Rent", name_based.name
   end
+
+  # Manual recurring transaction tests
+  test "create_from_transaction creates a manual recurring transaction" do
+    account = @family.accounts.first
+    transaction = Transaction.create!(
+      merchant: @merchant,
+      category: categories(:food_and_drink)
+    )
+    entry = account.entries.create!(
+      date: 2.months.ago,
+      amount: 50.00,
+      currency: "USD",
+      name: "Test Transaction",
+      entryable: transaction
+    )
+
+    recurring = nil
+    assert_difference "@family.recurring_transactions.count", 1 do
+      recurring = RecurringTransaction.create_from_transaction(transaction)
+    end
+
+    assert recurring.present?
+    assert recurring.manual?
+    assert_equal @merchant, recurring.merchant
+    assert_equal 50.00, recurring.amount
+    assert_equal "USD", recurring.currency
+    assert_equal 2.months.ago.day, recurring.expected_day_of_month
+    assert_equal "active", recurring.status
+    assert_equal 1, recurring.occurrence_count
+    # Next expected date should be in the future (either this month or next month)
+    assert recurring.next_expected_date >= Date.current
+  end
+
+  test "create_from_transaction automatically calculates amount variance from history" do
+    account = @family.accounts.first
+
+    # Create multiple historical transactions with varying amounts on the same day of month
+    amounts = [ 90.00, 100.00, 110.00, 120.00 ]
+    amounts.each_with_index do |amount, i|
+      transaction = Transaction.create!(
+        merchant: @merchant,
+        category: categories(:food_and_drink)
+      )
+      account.entries.create!(
+        date: (amounts.size - i).months.ago.beginning_of_month + 14.days, # Day 15
+        amount: amount,
+        currency: "USD",
+        name: "Test Transaction",
+        entryable: transaction
+      )
+    end
+
+    # Mark the most recent one as recurring
+    most_recent_entry = account.entries.order(date: :desc).first
+    recurring = RecurringTransaction.create_from_transaction(most_recent_entry.transaction)
+
+    assert recurring.manual?
+    assert_equal 90.00, recurring.expected_amount_min
+    assert_equal 120.00, recurring.expected_amount_max
+    assert_equal 105.00, recurring.expected_amount_avg # (90 + 100 + 110 + 120) / 4
+    assert_equal 4, recurring.occurrence_count
+    # Next expected date should be in the future
+    assert recurring.next_expected_date >= Date.current
+  end
+
+  test "create_from_transaction with single transaction sets fixed amount" do
+    account = @family.accounts.first
+    transaction = Transaction.create!(
+      merchant: @merchant,
+      category: categories(:food_and_drink)
+    )
+    entry = account.entries.create!(
+      date: 1.month.ago,
+      amount: 50.00,
+      currency: "USD",
+      name: "Test Transaction",
+      entryable: transaction
+    )
+
+    recurring = RecurringTransaction.create_from_transaction(transaction)
+
+    assert recurring.manual?
+    assert_equal 50.00, recurring.expected_amount_min
+    assert_equal 50.00, recurring.expected_amount_max
+    assert_equal 50.00, recurring.expected_amount_avg
+    assert_equal 1, recurring.occurrence_count
+    # Next expected date should be in the future
+    assert recurring.next_expected_date >= Date.current
+  end
+
+  test "matching_transactions with amount variance matches within range" do
+    account = @family.accounts.first
+
+    # Create manual recurring with variance for day 15 of the month
+    recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 100.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: 1.month.ago,
+      next_expected_date: Date.current.next_month.beginning_of_month + 14.days,
+      status: "active",
+      manual: true,
+      expected_amount_min: 80.00,
+      expected_amount_max: 120.00,
+      expected_amount_avg: 100.00
+    )
+
+    # Create transactions with varying amounts on day 14 (within ±2 days of day 15)
+    transaction_within_range = Transaction.create!(merchant: @merchant, category: categories(:food_and_drink))
+    entry_within = account.entries.create!(
+      date: Date.current.next_month.beginning_of_month + 13.days, # Day 14
+      amount: 90.00,
+      currency: "USD",
+      name: "Test Transaction",
+      entryable: transaction_within_range
+    )
+
+    transaction_outside_range = Transaction.create!(merchant: @merchant, category: categories(:food_and_drink))
+    entry_outside = account.entries.create!(
+      date: Date.current.next_month.beginning_of_month + 14.days, # Day 15
+      amount: 150.00,
+      currency: "USD",
+      name: "Test Transaction",
+      entryable: transaction_outside_range
+    )
+
+    matches = recurring.matching_transactions
+    assert_includes matches, entry_within
+    assert_not_includes matches, entry_outside
+  end
+
+  test "should_be_inactive? has longer threshold for manual recurring" do
+    # Manual recurring - 6 months threshold
+    manual_recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 50.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: 5.months.ago,
+      next_expected_date: 15.days.from_now,
+      status: "active",
+      manual: true
+    )
+
+    # Auto recurring - 2 months threshold with different amount to avoid unique constraint
+    auto_recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 60.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: 3.months.ago,
+      next_expected_date: 15.days.from_now,
+      status: "active",
+      manual: false
+    )
+
+    assert_not manual_recurring.should_be_inactive?
+    assert auto_recurring.should_be_inactive?
+  end
+
+  test "update_amount_variance updates min/max/avg correctly" do
+    recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 100.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: Date.current,
+      next_expected_date: 1.month.from_now,
+      status: "active",
+      manual: true,
+      occurrence_count: 1
+    )
+
+    # Record first occurrence with amount variance
+    recurring.record_occurrence!(Date.current, 100.00)
+    assert_equal 100.00, recurring.expected_amount_min.to_f
+    assert_equal 100.00, recurring.expected_amount_max.to_f
+    assert_equal 100.00, recurring.expected_amount_avg.to_f
+
+    # Record second occurrence with different amount
+    recurring.record_occurrence!(1.month.from_now, 120.00)
+    assert_equal 100.00, recurring.expected_amount_min.to_f
+    assert_equal 120.00, recurring.expected_amount_max.to_f
+    assert_in_delta 110.00, recurring.expected_amount_avg.to_f, 0.01
+
+    # Record third occurrence with lower amount
+    recurring.record_occurrence!(2.months.from_now, 90.00)
+    assert_equal 90.00, recurring.expected_amount_min.to_f
+    assert_equal 120.00, recurring.expected_amount_max.to_f
+    assert_in_delta 103.33, recurring.expected_amount_avg.to_f, 0.01
+  end
+
+  test "identify_patterns_for updates variance for manual recurring transactions" do
+    account = @family.accounts.first
+
+    # Create a manual recurring transaction with initial variance
+    manual_recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 50.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: 3.months.ago,
+      next_expected_date: 1.month.from_now,
+      status: "active",
+      manual: true,
+      occurrence_count: 1,
+      expected_amount_min: 50.00,
+      expected_amount_max: 50.00,
+      expected_amount_avg: 50.00
+    )
+
+    # Create new transactions with varying amounts that would match the pattern
+    amounts = [ 45.00, 55.00, 60.00 ]
+    amounts.each_with_index do |amount, i|
+      transaction = Transaction.create!(
+        merchant: @merchant,
+        category: categories(:food_and_drink)
+      )
+      account.entries.create!(
+        date: (amounts.size - i).months.ago.beginning_of_month + 14.days,
+        amount: amount,
+        currency: "USD",
+        name: "Test Transaction",
+        entryable: transaction
+      )
+    end
+
+    # Run pattern identification
+    assert_no_difference "@family.recurring_transactions.count" do
+      RecurringTransaction.identify_patterns_for(@family)
+    end
+
+    # Manual recurring should be updated with new variance
+    manual_recurring.reload
+    assert manual_recurring.manual?
+    assert_equal 45.00, manual_recurring.expected_amount_min
+    assert_equal 60.00, manual_recurring.expected_amount_max
+    assert_in_delta 53.33, manual_recurring.expected_amount_avg.to_f, 0.01 # (45 + 55 + 60) / 3
+    assert manual_recurring.occurrence_count > 1
+  end
+
+  test "cleaner does not delete manual recurring transactions" do
+    # Create inactive manual recurring
+    manual_recurring = @family.recurring_transactions.create!(
+      merchant: @merchant,
+      amount: 50.00,
+      currency: "USD",
+      expected_day_of_month: 15,
+      last_occurrence_date: 1.year.ago,
+      next_expected_date: 1.year.ago + 1.month,
+      status: "inactive",
+      manual: true,
+      occurrence_count: 1
+    )
+    # Set updated_at to be old enough for cleanup
+    manual_recurring.update_column(:updated_at, 1.year.ago)
+
+    # Create inactive auto recurring with different merchant
+    auto_recurring = @family.recurring_transactions.create!(
+      merchant: merchants(:amazon),
+      amount: 30.00,
+      currency: "USD",
+      expected_day_of_month: 10,
+      last_occurrence_date: 1.year.ago,
+      next_expected_date: 1.year.ago + 1.month,
+      status: "inactive",
+      manual: false,
+      occurrence_count: 1
+    )
+    # Set updated_at to be old enough for cleanup
+    auto_recurring.update_column(:updated_at, 1.year.ago)
+
+    cleaner = RecurringTransaction::Cleaner.new(@family)
+    cleaner.remove_old_inactive_transactions
+
+    assert RecurringTransaction.exists?(manual_recurring.id)
+    assert_not RecurringTransaction.exists?(auto_recurring.id)
+  end
 end