A payment record answers one question
A billing system can show that a payment succeeded, failed or was refunded. That is useful, but it may not include the offer shown before signup or a record of the customer’s agreement.
Those details may be stored in checkout logs, a receipt, a consent field or a dated terms version. The available information depends on the business’s setup and what each system keeps.
Connect the records carefully
Where the source supports it, link the customer, subscription, offer version and agreement event. Keep the time and source with each item. If the source does not show which version a customer saw, leave that connection unknown instead of inferring it from a later charge.
Give historical details a label
A spreadsheet or staff entry can add useful context, but it is different from a checkout record captured at signup. Mark who supplied the information and when it was imported or entered. Preserve later corrections as changes, not as if they were part of the original record.