Keeping records and how long to keep them
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 6 min
In short
For a crypto return, retaining the history that supports your calculation is essential. Which documents must be kept and for how long is set by the rules, and what counts is whether you can produce them when asked. Save your own copies before an exchange shuts down and the history becomes unreachable. Take periods and requirements from National Tax Agency guidance and consult a tax professional.
Key points
- Which documents to keep, and for how long, is set by the rules
- When an exchange or service closes, its history stops being retrievable
- Separate requirements may apply to records kept in electronic form
- A document you have no copy of is, in practice, one that does not exist
Definition
Keeping the transaction history, receipts and other material supporting a return, for the prescribed period, in a state where they can be produced on request.
Every figure on a return rests on something. For crypto, that something is the transaction history. If you cannot show which transactions were aggregated and how, when the content is later examined, the explanation does not hold. Retention is not a formality — it protects your own filing.
Which documents must be kept and for how long is set by the rules. Because the periods themselves can be amended, this site does not state a number of years. Check the current requirements in National Tax Agency guidance.
The crypto-specific problem is availability. Exchanges close, and regulatory changes can end service to Japanese residents. Even in normal operation, the downloadable history may be limited to a certain window. Waiting until you need it can mean it is no longer there. Export periodically during the year and keep the files under your own control.
Think about where they live, too. History that merely 'exists' inside an exchange dashboard is not the same as a copy on your own machine or cloud storage. Keep copies in more than one place, against hardware failure or losing an account, and name files with the year and the venue so you can find them later.
Note also that keeping books and documents electronically may carry its own set of requirements. Dropping CSVs into a folder is not automatically sufficient. If you operate as a business, confirm this point with a tax professional in particular.
Watch out for
- · This page is a general orientation, not tax advice
- · Retention periods and electronic-record requirements are set by the rules — check National Tax Agency guidance
- · Exchange history is not permanently retrievable; save it while the year is still current
Frequently asked questions
Do screenshots count as records?
They are far better than nothing, but they do not necessarily substitute for formal history data. Obtain CSV transaction history wherever possible and keep screenshots as supporting material. Confirm the requirements with a tax professional.