Yes — they are entirely separate filings with separate agencies. Revenue Department registration covers the employee's tax identification and withholding tax setup. Social Security registration covers contribution obligations and the employee's entitlement to social security benefits. Both are required for a new employee. UnionSPACE handles each as a distinct service; if both are needed simultaneously, we coordinate them to minimise turnaround time.

The employer is still required to withhold and remit the tax for that payroll period. Without a TIN, the withholding cannot be correctly attributed to the employee on the Por Ngor Dor 1 return — creating a reporting gap. Once the TIN is issued, the prior months' withholding must be correctly attributed retrospectively. We advise on how to handle this in the payroll guidance memo and provide guidance on the correction process where it applies.

Potentially, depending on the employee's country of tax residence and the terms of the applicable DTA. Some DTAs limit or exempt Thai tax on employment income earned by short-term assignees or individuals who remain tax-resident in their home country. However, treaty relief must be applied correctly from the outset — it cannot simply be claimed retrospectively without the correct supporting documentation. We assess the employee's treaty position as part of the initial tax review and advise on whether relief applies before the first payroll is run.

Foreign employees who work in Thailand on a valid work permit and receive employment income are generally subject to Social Security contributions in the same way as Thai employees — both the employer and employee contribute at the prescribed rate. The Social Security Office registration is a separate filing from this Revenue Department registration service. UnionSPACE handles SSO registration as a distinct service and can coordinate both if needed.

An employer who fails to withhold and remit income tax correctly is liable to the Revenue Department for the unremitted tax — in addition to surcharges and penalties. The liability attaches to the employer even where the failure results from the employee not having a TIN at the time of payment. This is why registration before or as close as possible to the first payroll is important — it limits the period during which the employer's reporting is incomplete.