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Apply your rules to transactions you already have

Last updated October 13, 2026

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Your rules categorize new transactions as they come in. Transactions that were already in your ledger when you created or changed a rule keep their category until you ask your AI to apply your rules to them. Applying takes two steps: a preview of what would change, then the save. If you don't have a rule yet, start with create a rule.

When you need this

  • You made a rule without applying it, and want it to cover the transactions already there.
  • You changed a rule's pattern or category, and want existing transactions to follow the change.
  • You imported a file or added transactions with rules turned off, and now want your rules on them.

How to do it

  1. Ask your AI to apply your rules. Name a date range or an account to limit it, or leave both out to cover the whole ledger.
  2. Your AI runs a preview first: how many transactions would change, with a few examples. Ask to see it before anything is saved.
  3. Tell your AI to go ahead. It saves the changes and tells you how many transactions it categorized.
Try asking

Create a rule that puts Metro Transit in Transportation without applying it to past transactions, then apply my rules to last month.

Try asking

Make a rule putting Daily Grind Coffee under Coffee, but don't apply it yet. Then show me what applying my rules to Everyday Checking would change, without saving anything.

What you'll see

For the first prompt, your AI saves the rule, then previews your rules on last month and applies them. It may show you the preview and ask before saving. Last month's two Metro Transit charges move to Transportation. Earlier Metro Transit charges keep their category.

For the second, your AI saves the rule and shows a preview: the 48 Daily Grind Coffee charges on Everyday Checking would go to Coffee. No transaction changes until you ask your AI to apply.

What the preview shows

  • How many transactions your rules match, and how many would change. A transaction already in the rule's category doesn't change.
  • Up to 20 examples, each with the category it would get and the rule that sets it.
  • How many transactions are left alone because you set their category yourself, or because you pinned that merchant in your AI's memory.
  • Transactions where two rules disagree, with the rule that wins. The rule created first wins. See when two rules match the same merchant.
  • Transactions updated in the last 90 days where a rule would replace a category set by your bank or another rule. Categories that came in with an import aren't flagged.

Good to know

  • New transactions don't need this. Imports, transactions your AI adds without a category, and new bank transactions get your rules' categories as they're added. Bank transactions are added at your next session, when you open the web app or ask your AI something. See a rule didn't categorize a transaction.
  • The preview always comes first. Pennyweight saves an apply only with the confirmation code from its preview, so a preview always runs. Your AI may show it to you or go straight on to the save; ask to see it if you want to. See why your AI shows a preview before saving.
  • Only active rules run. A rule you turned off is skipped. You can also ask your AI to run one rule on its own. See test, edit, turn off or delete a rule.
  • Your categories stay. Rules never change a category you set yourself. Bank categories and categories from an imported file are replaced. See who wins: you, your rules, or the bank.
  • One ledger at a time. Your AI runs the rules of your active ledger, or of the ledger that holds the account you name, and only on that ledger's transactions.
  • Very large ledgers. One pass looks at about 20,000 transactions. Past that, the result says it covered only part of them. Ask your AI to run your rules again by date range or by account to cover the rest.
  • See what a rule did. Rules don't keep a count of their matches. Ask your AI to find the transactions a rule categorized instead. Rule changes from before Pennyweight began recording which rule set a category don't show up.
  • You can still change the result. A category a rule set is recorded as the rule's, so when you change it yourself later, your choice shows.
  • Rule or one-time fix? Not sure a rule is the right tool? See rules or a one-time cleanup.
  • Create a categorization ruleTell your AI once which category a merchant belongs in. It saves a rule that sorts that merchant's new transactions, and can sort existing ones too.
  • Test, edit, turn off or delete a ruleCheck how many transactions a rule matches before you apply it, then change its pattern or category, turn it off, or delete it.
  • When two rules match the same merchantIf two of your rules match the same charges with different categories, the rule created first wins. Here is how to spot the clash and pick the winner.
  • A rule didn't categorize a transactionYou made a rule, but a matching transaction is still uncategorized or has another category. Here is why a rule skips a transaction and how to fix it.