Electronic transaction data must be retained. Sorting out the authenticity and visibility requirementsInvoices you get by e-mail or online should be kept as data, not printed out
When invoices, receipts and similar documents are exchanged as electronic data, you are obliged to keep that data in electronic form. The NTA leaflet (June 2026) presents the retention requirements as two pillars: ensuring authenticity and ensuring visibility. It can be used first to check whether the way your business receives and stores data meets these requirements.
- ○Applies: Authenticity: take one of the four measures
- ○Applies: Visibility: provide a display, printer and the like
- ○Applies: Visibility: make data searchable by date, amount and counterparty
- ×Does not apply: Providing a display, printer and the like is not necessary
Key points
- Electronic books retention under the Electronic Books Maintenance Act has three categories: (1) electronic books retention (optional), (2) scanner retention (optional), and (3) electronic transaction data retention (required for corporations and sole proprietors). Only electronic transaction data retention is mandatory.
- Ensuring authenticity means doing one of the following: receiving data with a timestamp; adding a timestamp promptly after receipt; exchanging and storing data in a system that keeps a history of corrections and deletions (or does not allow them); or drawing up, operating and keeping on file internal rules to prevent tampering.
- Ensuring visibility requires both providing a display, printer and the like, and making data searchable by the three items of date, amount and counterparty.
- For search, you need one of these measures: being able to search by date range and by a combination of two items, or being able to comply with requests for downloads during tax audits and the like.
What to do in practice
- List the routes by which you receive transaction documents electronically (e-mail attachments, cloud, EDI and so on) and decide where to store them.
- Decide which of the four authenticity measures you will use, and prepare internal rules if necessary.
- Check that data can be searched by date, amount and counterparty (using file names, an index record, accounting software and so on).
An invoice or receipt that arrives online is treated as the real document in its data form, not on paper. So the rule is to keep it as data, in a way that lets you find it later and shows nobody has secretly changed it.
- 1. ReceiveAn invoice arrives as data by e-mail or on a website
- 2. ProtectKeep it so it cannot be changed, or so any change is recorded
- 3. OrganizeMake it searchable by date, amount and the other party's name
- 4. ShowBe ready to show it on a screen or on paper
Points
- Keep invoices you receive as data in their data form.
- Store them in a way that shows they have not been changed afterward.
- Make sure you can find them by "when, how much, and which company."
What the words mean
- Electronic transactions (電子取引)
- Exchanging invoices, receipts and other documents by e-mail or over the internet
- Timestamp (タイムスタンプ)
- A mark of time that proves "this data existed at this moment"
- National Tax Agency (NTA): NTA: Why not advance digitalization further by using the electronic books retention system? (June 2026)
- National Tax Agency (NTA): NTA: Overview of the Electronic Books Maintenance Act
This article summarizes and explains materials published by government agencies and is not advice on any individual case. Rules can change, so for actual procedures and decisions always check the latest original materials and consult professionals such as tax accountants or labor and social security attorneys. English, Simplified Chinese and Traditional Chinese versions are translations prepared from the Japanese articles for convenience. If anything differs, the Japanese text and the original source take precedence.