English interface
Thai late-tax surcharge calculator
Calculate the 1.5% monthly-or-part surcharge from a user-confirmed period count.
Limited scopeHigh-impactRevenue Code section 27 · Confirm period count
Saves this tool's name on this device only (up to 20). No form values.
Only visible result text is included. Form fields are not read. Review sensitive values before sharing.
How to use it
- Confirm that the stated scope applies.
- Enter the checked base and select the applicable option.
- Review the breakdown, source and exclusions.
Important limitation
Calculates only section 27 surcharge from a user-confirmed month-or-part count; excludes penalties, criminal fines, exceptions and extensions.
The interactive form is fully localized in English.
Reviewed 2026-09-16; next review 2026-12-16.
Available for trial use while reference examples or test cases are being expanded.
Traceable review record
Site changelogReview history
This is the recorded review history available in the repository, not an inferred release history. Dates are added only when evidence is recorded.
- Current review snapshot recorded
Available for trial use while reference examples or test cases are being expanded.
Method version: review-2026-09-16