The mechanics: SA109 boxes 28 and 29, then quantify everything
HMRC's helpsheet HS266 sets out the process. The foreign income and gains (FIG) regime is claimed on the SA109 pages of a Self Assessment return: box 28 claims relief on qualifying foreign income and box 29 on qualifying foreign gains. You then report each relieved amount on the normal supplementary pages, for example the SA106 for foreign investment income, the SA108 for gains, or the SA103F and SA104F where foreign trading or partnership income is involved. HMRC's Residence and FIG Regime Manual at RFIG42100 is explicit that the claim is made on a source by source basis and that the amount of relief must be quantified in the return. A claim that quantifies nothing at all is invalid. Getting a figure wrong does not invalidate the claim, but relief only attaches to what you actually declared and claimed, which is why the numbers deserve care the first time. Our SA109 walkthrough goes box by box.
Deadlines for the first FIG filing season
The regime started on 6 April 2025, so 2025/26 returns are the first ever FIG returns and the filing season is running now. A paper return is due by 31 October 2026 and an online return by 31 January 2027. The claim itself has a slightly longer life: under RFIG42300 a FIG claim for 2025/26 can be made, amended or withdrawn up to 31 January 2028, which matters if you file first and refine the claim later. Remember the trade-off before you commit: a claim costs you the personal allowance and the CGT annual exempt amount for that year, and it is a fresh decision each year of your four-year window. If you are still weighing up whether to claim at all, start with our overview of the FIG regime and the deadlines by arrival year.
Why you cannot just use HMRC's free service
The most common surprise is that HMRC's free online filing service does not support the SA109 at all, so it cannot submit a FIG claim. That leaves three routes: buy commercial tax software that handles the SA109, appoint an agent who files through professional software, or file on paper by the earlier October deadline. Software will transmit the boxes, but it will not tell you whether a claim is worth making, which sources qualify, or how to quantify a part-year foreign employment figure, which is where most of the value sits. Our guide on whether you need an accountant for the FIG regime walks through that decision honestly.
How Horizon files FIG returns
FIG returns are exactly the returns Horizon UK Tax Solutions specialises in. The practice is founder-led by a Chartered Tax Adviser with over 10 years experience, including 7 at a Big Four firm, and files SA109 returns through professional software as standard. We confirm your qualifying years, run the claim versus no-claim arithmetic, quantify each source properly and file the whole return for a fixed fee agreed upfront: non-resident and expat returns from £550, complex returns from £750. If you want a second pair of eyes before the 31 January 2027 deadline, book a free 30-minute clarity call or see our non-dom and residency services.