About the document
- Who files:
- A taxpayer claiming child allowances beyond the lines of the attachment
- Where to submit:
- With the ภ.ง.ด.90/91 return at the Revenue Office
- Authority:
- Thai Revenue Department (กรมสรรพากร)
- Country:
- Thailand
- Category:
- Personal income tax
- How to fill:
- Cards with hints → original form → PDF
- Price:
- Free
- Last updated:
- Official source:
- https://www.rd.go.th/67335.html
What this document is
This is the official Thai Revenue Department (กรมสรรพากร) sheet «ใบแสดงรายละเอียดการลดหย่อนบุตรเพิ่มเติม». It is attached to the personal income tax return ภ.ง.ด.90 or ภ.ง.ด.91 together with the allowance attachment (ใบแนบแสดงรายละเอียดรายการลดหย่อนและยกเว้นหลังจากหักค่าใช้จ่าย) when that attachment has too few lines for all your children.
The sheet has two parts: children with the 30,000 baht allowance, and biological children from the second onward born in 2018 (พ.ศ. 2561) or later, who carry a 60,000 baht allowance. There are no amounts on the sheet: the child allowance is calculated and entered on the attachment.
Who files it and where
- a taxpayer claiming child allowances on ภ.ง.ด.90 or ภ.ง.ด.91 when there are more children than lines on the allowance attachment;
- it goes with the return and the attachment to the Area Revenue Office (สำนักงานสรรพากรพื้นที่) or with a paper return;
- according to the 2568 ภ.ง.ด.90/91 instructions, the paper return for tax year 2568 is due by the end of March 2569 (2026); check online deadlines on the Revenue Department website.
What the form asks
- which return it belongs to (ภ.ง.ด.90 or ภ.ง.ด.91) and the tax year in the Buddhist Era;
- the taxpayer's ID and name in Thai script;
- the spouse's ID and name, if married;
- children's 13-digit ID numbers, separately for the 30,000 and 60,000 baht allowances; the number of children in each part is counted automatically.
What to have at hand
- the children's Thai ID cards or birth certificates for their 13-digit numbers;
- your ID card and your spouse's details;
- the completed ภ.ง.ด.90/91 return and the allowance attachment.
Whether extra documents are needed (for example proof of studies for a child over 20) — ask the Revenue Office.
How to fill it in with FoxDocs
- Answer the chat questions: the return, the year, your details and the children's IDs.
- FoxDocs puts each digit in its box, ticks the return, writes the year and counts the children.
- Download the PDF, check it and attach it to your return.
Source
Official Revenue Department forms page for 2568: rd.go.th — personal income tax forms 2568. The page links to this sheet in the 2566 folder — there is no separate 2568 edition. Checked 2026-10-13. This is not tax advice.