Why Foreign Accounting Software Keeps Failing in Thailand — Three Everyday Rules

By Dissai Pindatisha, Founder, Simply & Fine Solutions · Published 10 Oct 2026 · Updated 10 Oct 2026

Three everyday rules explain why foreign accounting software keeps failing in Thailand.

Three everyday rules

3% — withholding tax on most service payments. Deducted at source, on every vendor payment, with a certificate the vendor legally needs from you.

7% — VAT, reported monthly on ภ.พ.30 (PP.30), reconciled line by line against every invoice you issued and every bill you received.

Post-dated cheques — handed over today, dated for a later clearing date, sitting in a liability account the whole time, tracked by cheque number until they clear.

None of these are edge cases

They're Tuesday. Most global ERPs handle none of the three natively. So the finance team ends up with the software for some of it, and Excel for the rest — which means month-end is a reconciliation exercise between two systems that were never supposed to disagree.

That gap is the entire reason our practice exists. See how we handle it in Odoo Thai accounting.

Simply & Fine Solutions — Odoo implementor, Bangkok. ISO/IEC 29110 certified. More insights