Which way to rename files for the Electronic Books Preservation Act? — manual, Windows software, CSV list and automatic reading compared
There are roughly four ways to put the date, counterparty and amount into the file names of invoices and receipts. Which one suits you depends on how many files you get each month, whether you use Windows or a Mac, and where the date and amount come from.
Updated 2026-09-27. Details of other products were checked on their official pages on this date. They may have changed, so check the official pages before use.
Summary
- Up to about 10 files a month, doing it by hand is enough. Decide on the order of the name and stick to it.
- If you use a Windows PC and want searching and long-term storage handled in the same place, Windows software (for example I-O DATA's "Meimei-kun") suits you.
- If a list of dates, counterparties and amounts already exists in your accounting software or spreadsheet, a tool that renames files in bulk from a CSV list is fastest.
- If you have no such list and open each PDF to read it, a tool that reads the PDF contents automatically (such as Dencho Rename) saves effort.
The four methods compared
| Method | Where the date, counterparty and amount come from | Computer | Cost | Suits you when |
|---|---|---|---|---|
| By hand | You open the PDF, read it and type the name | Any | Free | Up to about 10 files a month |
| Windows software (e.g. Meimei-kun) | The software reads the file contents and fills them in (it also reads images and PDFs without text by OCR) | Windows 10 and 11 | Free version available; paid version with support | You work on Windows and want naming, searching and long-term storage on disc in one place |
| Tool that renames from a CSV list (e.g. KirokuKit) | A CSV list (date, counterparty, amount) that you prepare | Any computer with a browser | Free version available | A list already exists in your accounting software or spreadsheet |
| Browser tool that reads the PDF contents (Dencho Rename) | The tool reads the text inside the PDF; you check and correct it in a table | Any computer with a browser (Windows, Mac, iPad) | Free for up to 5 files at a time; paid plan 480 yen a month or 3,980 yen a year | You have no list and read each PDF by opening it; you use a Mac |
What each method involves
By hand
Open the PDF, read the date, counterparty and amount, and rename the file in Explorer or Finder. No tools are needed, but it takes longer as the number of files grows, and separators and date formats tend to drift. Decide the order and format first (file naming rules).
Windows software
I-O DATA's "Meimei-kun" is a Windows application made of a tool for renaming and searching and a tool for long-term storage on disc. It reads file contents to fill in the fields, and reads images and PDFs without text by OCR. There is a free version and a paid version with support. It runs on Windows 10 and 11, not on a Mac, and must be installed on the PC.
Tool that renames from a CSV list
KirokuKit's batch rename and index maker takes your PDFs or images and a CSV list of dates, counterparties and amounts in the browser, renames them in bulk and returns them in a ZIP together with an index CSV. It does not read the file contents, so the list has to be made somewhere. If your accounting software can export such a list, or you already keep one in a spreadsheet, it is a fast method with no retyping.
Browser tool that reads the PDF contents
Dencho Rename reads the date, amount and counterparty from the text inside each PDF you drop, lists them in a table, names all files in the same order and returns them in a ZIP. Nothing to install, and files are processed only in your browser, never sent to a server. Reading is not perfect, so check and correct the table before saving. PDFs with embedded text are free for up to 5 files at a time; reading photos and scans and the index book CSV are paid. It has no search or long-term storage features, so you keep and search files with folders and file names, or with an index book.
Which to choose
- Up to about 10 files a month, start by hand. Once the order of the name is decided, that alone prepares you for the search requirement.
- If a list of dates, counterparties and amounts already exists, use a tool that renames from the CSV list. It is fast because there is no reading to check.
- If you work only on Windows and want searching and storage on disc in one piece of software, choose the Windows software.
- If you have no list and read each PDF by opening it, or you work on a Mac or iPad, a browser tool that reads the PDF contents suits you. First try the free 5 files to see how well your own invoices are read.
Whichever method you use, the fields and their order in the file name are the same. Keeping electronic transaction data also needs measures against tampering in addition to the search requirement (the search requirement explained).
FAQ
Can I combine methods?
Yes. As long as the order and format of the file names match, it does not matter which tool named them. For example, you can name files by hand day to day and use a tool only for the batch that arrives at month end.
How accurate is the automatic reading?
With Dencho Rename, all 50 fields such as date, counterparty and amount were read correctly on 10 invoice and receipt PDFs with embedded text (measured 2026-09-15). Fields without a label, such as document numbers, and photos or scans can be misread, so check the table before saving.
Try Dencho Rename
No sign-up needed. For PDFs with embedded text, you can read and name up to 5 files at a time for free.
Sources
- I-O DATA, "Meimei-kun" product page and specifications (in Japanese, viewed 2026-09-27)
- KirokuKit, batch rename and index maker (free version) (in Japanese, viewed 2026-09-27)
- National Tax Agency, Electronic Books Preservation Act Q&A [Electronic transactions] (July 2026, in Japanese)