Bulk-rename invoice and receipt PDFs that arrive by email — attachments and body-only emails
Invoice and receipt PDFs that arrive by email are named differently by each sender, such as 請求書.pdf ("invoice.pdf") or invoice.pdf. When you download two files with the same name, the browser only adds a number, as in 請求書 (1).pdf. With those names you cannot find files by date, counterparty or amount. This page shows how to collect a month of PDFs in one folder and rename them all at once.
Updated 2026-10-03. Gmail's screen labels and steps were checked against Gmail Help up to this date.
Summary
- When an invoice arrives as an attachment, keep only the attachment. When the amount and other details are written in the email body, keep the email itself as a PDF (National Tax Agency Q&A, Q6 and Q53).
- At a fixed time, such as once a month, gather the PDFs that arrived that month into one folder.
- Put the transaction date, counterparty and amount in the file name, in the same order for every file. Example:
20260930_SampleCo_11000.pdf - Drop the PDFs into Dencho Rename together, and it reads the date, amount and counterparty and gives every file a name in the same order. Free for up to 5 files at a time.
Collect the emailed invoices as PDFs
How you prepare the PDF depends on how the invoice arrives.
| How it arrives | How to prepare it | Q&A |
|---|---|---|
| An invoice or receipt PDF is attached | Download the attachment. You do not need to keep the email | Q6 |
| The amount and other details are written in the body (order confirmations, monthly usage notices and so on) | Save the email as a PDF from the print dialog | Q6, Q53 |
| The invoice is downloaded from a link in the email | Download the PDF from the issuer's website | Q36 |
| The attached PDF has a password | You may remove the password before saving. Dencho Rename cannot open password-protected PDFs | Q42 |
| An Excel or Word invoice is attached | You may convert it to PDF before saving | Q42 |
If you use Gmail in a browser on a computer, do the following (Gmail Help).
- Attachments: open the email, hover over the attachment at the bottom, and click the download icon. The file goes to the browser's download folder
- Body-only emails: open the email, choose "Print" from the More icon (three vertical dots) at the top right, and save as PDF in the browser's print dialog (in Chrome, set Destination to "Save as PDF"; in Safari on a Mac, use "PDF" at the bottom left of the print dialog, then "Save as PDF")
You can find a month of emails with the Gmail search box. For example, for emails with a PDF attachment that mention an invoice or receipt and arrived in September, enter {invoice receipt} has:attachment filename:pdf after:2026/09/01 before:2026/10/01.
Rename them all with Dencho Rename
- Open the tool page and drop the PDFs from the folder in together
- The date, counterparty and amount appear in a table. Check them against the PDF preview on screen, and fix any that are wrong
- Choose the order of the name and the date format (the default is date_counterparty_amount)
- Press download to save the renamed PDFs as a ZIP (a single file is saved as a PDF)
If you received the same invoice in two emails or downloaded it twice, files with the same content go into the table only once. When two files get the same date, counterparty and amount and their names would collide, _2, _3 and so on are added to the end.
The PDFs are processed only inside your browser and are never sent to a server. There is nothing to install and no sign-up.
What is read from an emailed PDF
| Field | Where it is read from | Example |
|---|---|---|
| Transaction date | For invoices, the invoice or issue date (請求日, 発行日); for receipts, the receipt or payment date (領収日, 支払日) and similar fields. In a PDF printed from Gmail, the order or payment date in the body is read, and the print date and time that the browser adds at the top of the page is not used. If the body has no date field, the date the email was received is read | 2026-09-30 |
| Amount | The amount billed or total (ご請求金額, 合計金額, 合計) and similar. Amounts on subtotal (小計) and consumption tax (消費税) lines are not used | 11000 |
| Counterparty | The company name written on the document. In a PDF printed from Gmail, the sender's email address is not put into the counterparty | Sample Co., Ltd. |
| Document type | The title, such as 請求書 (invoice) or 領収書 (receipt). Whether to put it in the file name is a setting | Invoice |
Attached PDFs were checked with invoices and receipts actually received and with invoice Excel templates saved as PDF. PDFs printed from Gmail were checked with test PDFs laid out like Gmail's print view, not yet with real emails. Reading is not perfect, so check the table before saving.
Keep the date and counterparty consistent
An emailed invoice has several dates: the invoice date, the order or payment date in the body, and the date the email was received. Pick one and use it for every file, so nothing is missed when you search by date range. Dencho Rename reads the date written on the document first, so if you want the received date, fix it in the table.
The sender's display name (such as "XX Support") can differ from the company name on the invoice. Dencho Rename reads the company name on the document. Decide on one form for each name and fix any that differ in the table. On the paid plan, add it to the counterparty dictionary and it is replaced automatically from then on.
Frequently asked questions
How many files can I process at once?
On the free plan, up to 5 files can be in the table. After saving, clear them from the table and process the next 5. The paid plan (480 yen a month or 3,980 yen a year) has no limit, and you can line up a few hundred files at once.
Can I just leave them in Gmail?
Q5 of the Q&A says that being able to view them in email software is not enough, because the data must be kept in a searchable state. Save them in a folder on your computer or in cloud storage, and make them findable by date, counterparty and amount through the file name.
Can I print them on paper instead?
Invoices and receipts received by email are electronic transaction data, so keeping only a paper printout is not enough. Keep them as data (Q5).
What if I receive a PDF scanned from paper?
A PDF with no text in it cannot be read on the free plan, so you type the values into the table. The paid plan reads text from the image, but accuracy is lower than for PDFs with text, so check the table.
Is anything needed besides the file name?
The file name covers the search requirement. Keeping electronic transaction data also requires measures against tampering, such as setting internal rules and following them (the search requirement explained, file naming rules).
Try Dencho Rename
No sign-up needed. For invoice and receipt PDFs received by email, you can read and rename up to 5 files at a time for free.