You need to send a copy of an ID card or personal document as a PDF and want to state what it’s for, or you’re sending dozens of pages the recipient will refer to by page. Here is how to add a watermark and page numbers, with advice from the Thai agencies concerned.
In short
- State the purpose of a document: use watermark PDF; Thai text works, and you can set the opacity, size and angle.
- Number the pages: use add page numbers and choose the position, format and starting number.
- Prevent editing: add a password with protect PDF.
Every tool runs in your browser. Your file is not uploaded.
What a watermark is, and why use one
Adobe describes a watermark as fixed text or an image added to a PDF to indicate ownership, show branding or mark content as confidential, and notes that unlike stamps, watermarks are embedded into the page.
Even Thailand’s courts use them: the Office of the Judiciary’s announcement on electronic filing requires printouts from the system to carry a watermark with the system’s symbol, plus the name of the person who printed it and the date and time.
What to write on copies of documents
The Department of Provincial Administration advises, for copies of ID cards:
- Draw two parallel lines from the bottom-left corner to the top-right.
- Write what it’s “for”, end with the word “only”, and put a # at the start and end of the text.
- Always add the date.
The OCPB (via the Government Public Relations Department) advises always writing the purpose, such as “for opening an account only”, adding the date, and writing it across the copy. Government Housing Bank gives the example “for … only” naming the transaction and the bank.
Example watermark: #For a job application at Company A only 30 Sep 2026#
The Department of Provincial Administration also notes that a Cabinet resolution of 2 October 2018 told government agencies to stop asking for ID card copies; if one still does, ask whether your card itself will do. For making the copy itself, see copying your ID card safely.
Adding a watermark
- Open watermark PDF and choose a file.
- Type the text; the default is “สำเนา” (copy).
- Adjust opacity, size and angle so it’s readable without hiding important content.
- Download the new file. The original isn’t changed.
Limits: our watermark is placed as a picture on the page, which keeps Thai text correct on every device, but a watermark doesn’t prevent editing; Adobe Acrobat even has a tool that removes watermarks. To prevent editing, add a password, and send only the documents the recipient actually asked for.
Adding page numbers
- Open add page numbers and choose a file.
- Pick a position: top or bottom, left, centre or right.
- Pick a format:
1,1 / 10orหน้า 1(Page 1). - Set the starting number, for example 3 after two cover pages, and the number size.
- Download the new file.
Where page numbers go on Thai official letters: we read the consolidated Regulation of the Office of the Prime Minister on Correspondence (to amendment No. 4, 2021) and found no clause fixing the position. Some institutions have their own manuals; Mahamakut Buddhist University’s, for instance, puts page numbers at the top right from page 2. Follow what the receiving agency asks for.
Filing with Thai courts by e-Filing: the e-Filing Version 3 manual for the public (FEB 2022 edition) requires attachments to be .pdf, .jpeg or .jpg, no more than 1 MB per document and 30 MB in total. If a file is too big, use compress PDF or split PDF.
Or do it in Word
If the source is a Word file, Microsoft explains you can add a watermark under Design › Watermark › Custom Watermark, and “Page X of Y” numbers under Insert › Page Number, then save as PDF.
Note
This article is based on the Department of Provincial Administration, Government Public Relations Department and Government Housing Bank websites, the consolidated Regulation on Correspondence on the Law Reform website, Mahamakut Buddhist University’s manual, the Office of the Judiciary’s announcement and manual, and Adobe and Microsoft help pages, read on 30 September 2026.
