[Glossary](https://blnkfinance.com/glossary) Transaction # What is a transaction in a ledger? Transaction A transaction is a movement of value from a source balance to a destination balance. It has an amount, a currency, a reference, and a status. Nothing else changes a balance. If the money moved in the product, the ledger has a transaction for it. ## How does a transaction work? You send source, destination, amount, and a unique reference. The ledger queues it, then applies, holds, or rejects it. Applied posts change settled balances. Inflight posts change inflight balances. Rejected posts change nothing. ## Transaction vs payment A payment is what the customer thinks happened on a rail. A transaction is what the ledger recorded. One payment can be several transactions: the customer debit, the fee, the clearing credit. If you store only the payment, you lose the path. ## What makes a transaction complete? A unique reference, two balances, and a precision that matches the currency. Skip the reference and retries double-post. Skip a side and you no longer have double-entry. Skip precision and the integer in the database is a different amount than the one you showed. In Blnk a transaction always has a source and a destination. Status follows the lifecycle. Look it up by reference or by id. See [transactions](https://docs.blnkfinance.com/transactions/introduction). Related terms - [Ledger](https://blnkfinance.com/glossary/ledger) - [Source and destination](https://blnkfinance.com/glossary/source-and-destination) - [Inflight](https://blnkfinance.com/glossary/inflight) - [Reference](https://blnkfinance.com/glossary/reference)