Our books were not kept properly and are a mess. How do we catch up?
Common causes: early bookkeeping handled part-time or by head office staff, several changes of accounting provider, invoices and receipts not collected monthly, and BOI and non-BOI business not separated.
1. Four steps to catch up
Collect source documents: statements for every bank account, sales and purchase invoices, contracts, payroll, filed tax returns and receipts, and prior-year financial statements.
Rebuild the books month by month: use bank statements as the backbone, match each item to invoices and contracts, and produce monthly accounts.
Reconcile filed tax returns: compare the rebuilt books with the VAT, withholding and annual income tax returns already filed, month by month, to find omissions and errors.
Correct and file amendments: file supplementary returns where needed and pay tax and surcharges; for material errors in prior-year financial statements, agree the treatment with the auditor.
2. The most common problems
| Problem | Risk |
|---|
| Lost invoices or invoices in the wrong name | Input VAT cannot be claimed and expenses cannot be deducted |
| Cash receipts and payments without documents | Books do not match reality and cannot be verified at audit |
| Shareholder loans or head office advances without agreements | May be treated as income or a disguised dividend |
| BOI and non-BOI income mixed together | Affects the exemption calculation and may lead to clawback |
3. How long does it take?
It depends on the period covered and how complete the records are. With complete records, a year of books can usually be rebuilt within a few weeks; the more that is missing, the longer it takes. We recommend a diagnostic first to size the work before agreeing a plan.
4. Basis and scope of service
Basis: Thai Accounting Act on bookkeeping and retention of documents; Revenue Code on supplementary returns, surcharges (1.5% per month) and penalties. Catch-up bookkeeping is based on real transactions and source documents; Z&X does not make adjustments without supporting documents.
Further reading: Urgent reminder: are your Thai accounts still a mess?
Related services: Accounting & Tax Outsourcing | Tax Health Check
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