Before sending a payslip, contract or copy of a document, we often want to hide parts of it: an ID number, a phone number, a bank account. The trouble is that the way many people do it doesn't remove anything.
What counts as personal data under the PDPA
Section 6 of Thailand's Personal Data Protection Act B.E. 2562 (2019) defines personal data as information about a person that identifies them, directly or indirectly, excluding data of deceased persons.
Section 26 lists sensitive data that may not be collected without explicit consent unless an exception applies: race, ethnicity, political opinions, cult, religious or philosophical beliefs, sexual behaviour, criminal records, health data, disability, trade union information, genetic data and biometric data.
According to the PDPC, the Act has been fully in force since 1 June 2022.
If the recipient doesn't need to see such data, hiding it before you send is the simplest way to reduce risk.
Why a black box is not enough
Drawing a black box, highlighting in black, or colouring text to match the background makes it invisible, but the original text is still in the file.
- The US National Security Agency's guide "Redacting with Confidence" explains that information hidden or covered in a computer document can almost always be recovered, and that the safe way is to remove it from the document.
- The US District Court for the Northern District of Alabama warns that edits made with drawing or commenting tools can be removed to reveal the text underneath.
- In 2019, a court filing by Paul Manafort's lawyers looked redacted, but anyone could copy the text under the black bars (reported by the ABA Journal).
How to redact properly
- Remove the text, don't just cover it.
- Remove hidden file data, such as the author and title.
- Check every page by eye, then search the result for the words or numbers you hid. If a search still finds them, they were not removed.
Redact with FileMyLove
Redact PDF follows these rules:
- It finds 13-digit Thai ID numbers, phone numbers, emails and bank account numbers automatically, or any words you type, and you can draw extra boxes.
- Pages with black bars are turned into images, so the text under the bars is gone from the file.
- It removes the file's author and title data.
- Your file is never uploaded. Everything runs in your browser and is cleared after you download.
Automatic search can miss text inside images or scans, so always check every page before saving.
Checklist before you send
- ID or passport numbers
- Phone numbers, emails, addresses
- Bank account numbers
- Dates of birth
- Signatures the recipient doesn't need
If you really must send an ID card copy, use ID card copy, which writes the purpose across it. To limit who can open a file, use Protect PDF.
Note
This article is general information from sources read on 27 September 2026. It is not legal advice.