Two tax years, one set of facts
| Period | UK relevance | Thailand relevance |
|---|---|---|
| 1 January to 5 April | Final part of the UK tax year. | Opening part of the Thai calendar tax year. |
| 6 April to 31 December | Opening part of the next UK tax year. | Remainder of the same Thai calendar tax year. |
| Company accounting period | Corporation Tax follows the company period and statutory deadlines. | May need reconciliation to Thai activity, entity accounts or permanent-establishment reporting. |
UK personal deadlines
The UK tax year ends on 5 April. Paper Self Assessment returns normally have an earlier deadline than online returns, and HMRC’s standard online service does not support SA109 non-residence pages.
Payments on account may continue from prior returns even after departure. Review rather than cancel them informally, because UK rent, work or other income can remain taxable.
Thai personal reporting
Thailand reports personal income by calendar year. Confirm the applicable return, deadline, extensions and tax-payment process with the Revenue Department or Thai adviser for the year concerned.
Reconcile foreign tax paid after the Thai return is prepared. The timing of final UK assessments may require professional handling of credit claims, supporting evidence or later adjustments.
Company and payroll cycle
Add the UK company’s accounts, Corporation Tax, confirmation statement, VAT and payroll dates. If there is a Thai company, permanent establishment or local payroll, add those statutory cycles separately.
Monthly and annual tasks should have named owners. An overseas director remains responsible for ensuring that delegated filings occur.
Monthly evidence routine
- Reconcile personal and company accounts
- Update UK and Thai day counts
- Identify days worked in each country
- Tag salary, fees, dividends, loans and expenses
- Match Thai remittances to their source
- Save exchange rates and tax-withholding certificates
- Review new contracts, staff or premises for company risk
Frequently asked questions
Why can I not simply copy my UK return into the Thai return?
The reporting periods differ and each country may classify and source income differently. Reconcile transactions to both periods and apply each country’s rules separately.
Can a non-resident file SA109 using HMRC’s normal online return?
HMRC says its ordinary online service cannot be used for the SA109 residence pages. Use compatible commercial software, the paper process by its deadline or a tax professional.
Should I track company and personal deadlines together?
Yes, in one master calendar, while keeping the obligations legally separate. This helps identify interactions between payroll, dividends, personal returns and company filings.