Remove ID, phone and bank card numbers from PDFs in bulk
Short answer: In "Secure redaction" mode, tick the number types. The software searches the text layer and scanned images for numbers that match the format and pass the check digit, removes them, and rewrites the whole file. The batch window can process an entire folder at once.
Steps
- Switch to secure redactionUnder "Work mode" at the top of the left panel, choose "Secure redaction".
- Tick the typesTicked by default: mainland China, Taiwan, Hong Kong and Thai ID numbers, Singapore NRIC/FIN, bank card numbers, Chinese and Thai mobile numbers, international phone numbers and email addresses. Add numbers from other countries as needed.
- Add custom keywordsFor information that cannot be recognized by format, such as names, employee numbers or medical record numbers, type it in or import it from the first column of a table.
- Find and reviewThe results list shows each match partly masked. Scanned pages are recognized in full with the standard model.
- SaveChoose black boxes or boxes labeled "Redacted". Residue is checked automatically after saving.
- Process in batchFor several files, open the batch window, add the folder, choose the operation "Secure redaction", and review the processing report when it finishes.
How numbers are recognized
| Type | How it is recognized |
|---|---|
| Mainland China ID number | 18 characters, check code verified per GB 11643 |
| Taiwan ID number | 1 letter + 9 digits, check code verified |
| Hong Kong ID number | 1–2 letters + 6 digits + check code in parentheses, check code verified |
| Thai ID number | 13 digits, check digit verified |
| Singapore NRIC/FIN | Letter + 7 digits + letter, check letter verified |
| Bank card number | 16–19 digits, verified with the Luhn algorithm |
| Mobile number (China, Thailand) | By number-range format |
| International phone number | Starts with +, 8–15 digits |
| Email address | By format |
To see which numbers would be found in a piece of text before you start, use the ID number format tester. It uses the same rules as the software and runs locally in your browser.
When numbers are not found
- The number is split across a line break;
- The scan quality is too poor and digits are misread (a number whose check digit fails is not treated as an ID number);
- The number is handwritten.
In these cases, add the number as a custom keyword, or handle it manually after confirming it in the preview.
FAQ
Are numbers with spaces or dashes recognized?
Yes. Spaces, dashes and parentheses between digits are ignored before matching, for example "138 0013 8000".
Will an ordinary string of digits be removed by mistake?
Every type that can be checked is validated by check digit or date, such as the ID number check code or the Luhn algorithm for bank card numbers. Ordinary digit strings rarely pass.