If you are planning to move your agency to Dubai and become non-resident for UK tax purposes, there is a specific corporation tax process you need to complete before you leave. It is not optional. And it is easy to get wrong if you do not know the rules.

The key point is this: your company's accounting period must be shortened to end on the date your agency becomes non-resident. You then file a final corporation tax return (CT600) for that shortened period. And you must pay any tax due before HMRC will treat the company as dormant or non-resident.

This is not a theoretical exercise. I have seen agency founders assume they can just close their UK company and pick up in Dubai. HMRC does not work that way. The UK corporation tax final period before moving is a real filing obligation with real deadlines and real penalties if you miss them.

Let me walk through exactly what you need to do, in the order you need to do it.

When Does Your Agency Become Non-Resident?

Your company becomes non-resident for UK tax purposes when its central management and control moves outside the UK. For most agency founders moving to Dubai, that means the date you:

  • Relocate to the UAE permanently (or for the foreseeable future)
  • Hold your board meetings in Dubai
  • Make key strategic decisions from your Dubai office
  • Cease to have a UK trading presence (if applicable)

HMRC will look at the substance of where your agency is managed, not just where you happen to be living. If you are still flying back to London every month to run the business from a WeWork in Shoreditch, HMRC may argue your company is still UK-resident.

Once you have established the date of change, that becomes the end of your final UK accounting period.

Shortening the Accounting Period

Normally, a company's accounting period runs 12 months. When a company becomes non-resident, the period is shortened to end on the date of change.

Here is a real example. Say your agency's normal accounting year runs from 1 April to 31 March. You move to Dubai on 15 September 2025. Your final UK accounting period will be from 1 April 2025 to 15 September 2025. That is 168 days, not 365.

This shortened period has consequences:

  • You must prepare accounts for that specific period, not a full year
  • Your corporation tax liability is calculated on profits earned during those 168 days only
  • You must file a CT600 for that period, even if it is shorter than 12 months
  • Any tax due must be paid within 9 months and 1 day of the period end (so by 16 June 2026 in this example)

Most accounting software like Xero or QuickBooks can handle a shortened period. But you need to tell your accountant the exact date. Do not guess. HMRC will not accept a "close enough" date.

What Happens to Pre-Move Profits?

All profits your agency earned up to the date of becoming non-resident are subject to UK corporation tax. There is no special relief for moving abroad. If you made £200k profit in the 168-day period, you pay corporation tax on that £200k.

The rate depends on your profit level:

  • If profits are under £50k for the shortened period (annualised), the small profits rate of 19% applies
  • If profits are over £250k (annualised), the main rate of 25% applies
  • Between £50k and £250k, marginal relief applies, giving an effective rate between 19% and 25%

Because the period is shorter than 12 months, you need to annualise your profits to work out which rate applies. Your accountant will do this. But be aware: a £40k profit over 168 days annualises to roughly £87k, which puts you in the marginal relief band. The actual tax bill will be somewhere between 19% and 25% on that £40k.

Filing the Final CT600

The CT600 for your final UK period is filed the same way as any other corporation tax return. You submit it through HMRC's online system, usually via commercial software or through your accountant's portal.

Key differences for a final return:

  • You must tick the box indicating this is the company's final return (box 4 on the CT600)
  • You must include the date the company became non-resident
  • You may need to include a statement explaining the change of residence
  • If the company will continue trading from Dubai, you may need to confirm it is not being wound up

The filing deadline is 12 months after the end of the shortened accounting period. So for our 15 September 2025 example, the CT600 is due by 15 September 2026. But the payment deadline is earlier: 9 months and 1 day after the period end, which is 16 June 2026.

Do not confuse the two. You can file the return later than the payment date, but you must pay the tax on time. Late payment interest runs from the due date, and it is not cheap.

Payment Before HMRC Considers the Company Dormant

This is the part that catches agency founders out. HMRC will not treat your UK company as dormant or non-resident until all outstanding corporation tax is paid. If you have an unpaid liability sitting on the company's record, HMRC will still chase it. They will still send reminders. They will still issue penalties.

You need to:

  • Calculate the exact corporation tax due for the shortened period
  • Pay it in full by the due date
  • Ensure the payment references the correct accounting period (use the 17-character AP reference from HMRC)
  • Confirm with HMRC that the company's record shows a nil balance

If you overpay, you can claim a repayment. If you underpay, you will get interest and potentially penalties. Get the calculation right first time.

What About Post-Move Profits?

Once your agency is non-resident, any profits it earns from trading in Dubai are outside the scope of UK corporation tax. But there is a catch: if your company continues to have a UK source of income (for example, a retainer from a UK client that is managed from the UK), that income may still be subject to UK tax.

Typically, if your agency is fully managed from Dubai and all trading activity happens from Dubai, then all profits are Dubai-sourced and not subject to UK corporation tax. But you need to be clean on this. If you are still taking UK client meetings from a rented desk in Soho, HMRC may argue your agency has a UK permanent establishment.

We covered this in more detail in our article on managing your agency's exit from the UK.

Directors' Loan Accounts and Final Period

If you have a directors' loan account balance when your agency becomes non-resident, you need to clear it. The rules are the same as for any other period:

  • If the loan is over £10k and interest-free, there is a benefit-in-kind to report on a P11D
  • If the loan is not repaid within 9 months of the year end, the company pays S455 tax at 33.75%
  • That S455 tax is repayable when the loan is repaid, but only if you claim it

If you are moving to Dubai, the cleanest approach is to repay any directors' loan before the final period ends. That way there is no outstanding balance to deal with from the UAE. You can always draw a new loan from the Dubai entity later.

VAT and Other Taxes

Corporation tax is not the only tax to consider when your agency becomes non-resident. You also need to deal with:

  • VAT: if your agency is still making UK supplies, you may need to remain VAT-registered even if non-resident. The VAT registration threshold is £90,000 turnover, but if you deregister and then need to re-register, it creates admin.
  • PAYE: if you have UK employees, you still need to operate payroll and file RTI returns. Your agency may need to remain as a UK employer even if non-resident.
  • IR35: if you use contractors, your agency's status as a medium or large business determines whether you need to issue Status Determination Statements. This does not change just because you move.

Each of these has its own rules for non-resident companies. Do not assume that moving to Dubai means you can ignore UK compliance entirely.

Practical Steps Before You Move

Here is the checklist I give to agency founders planning a Dubai move:

  1. Confirm the exact date your company will become non-resident
  2. Prepare accounts for the shortened period ending on that date
  3. Calculate the corporation tax liability (including marginal relief if applicable)
  4. Set aside the cash to pay it. Do not rely on future Dubai profits to cover it.
  5. File the final CT600 with the non-resident box ticked
  6. Pay the tax by the 9-month deadline
  7. Clear any directors' loan account balances
  8. Decide on VAT, PAYE, and other ongoing UK obligations
  9. Inform HMRC of the change of residence (you can do this via the CT600 or separately)

If you are working with an accountant who understands both UK and UAE tax, this process is straightforward. If you are trying to do it yourself or with an accountant who only handles standard UK companies, you risk missing a step.

As ICAEW qualified accountants, we handle these transitions regularly for agency founders moving to Dubai. The UK corporation tax final period before moving is a well-defined process. It just needs to be followed correctly.

What If You Change Your Mind?

If you move to Dubai but then return to the UK within a few years, your company may become UK-resident again. That means a new accounting period starts on the date of return. You would then file corporation tax returns for the period of non-residence as well, depending on the circumstances.

This is rare, but it happens. If you are unsure about your long-term plans, it is worth structuring the move so that it is reversible. That usually means keeping the UK company alive but dormant, rather than striking it off.

If you want to discuss your specific situation, get in touch with our team. We work exclusively with agency founders and understand the transition from UK to UAE trading.

The key takeaway is simple: plan your final UK corporation tax period before you move. Know the date. File the return. Pay the tax. Then you can focus on building your agency from Dubai without HMRC chasing you for a forgotten liability.