The tax year runs 6 April to 5 April, but your first year as a UK resident almost never lines up with that. You arrived on some specific date, and a salary that started before that date, kept being paid after it, doesn't get taxed the same way on both sides of the line.
Your arrival year usually splits into two
If you weren't UK resident for the whole tax year, HMRC's split year treatment can divide it into an overseas part and a UK part instead of treating the entire year as UK-resident. Broadly, you're taxed as a UK resident only for the UK part — worldwide income and gains — while the overseas part before your residence started is generally only taxed on UK-source income. Two of HMRC's eight split year cases specifically cover starting to have a UK home, which is the usual route for a new arrival. The detail — which case applies, and exactly which SA109 boxes it changes — is covered in split year treatment for arrivals, box by box.
Split year treatment isn't the same as OWR
This is where it gets easy to conflate two separate reliefs:
- Split year treatment decides which part of your arrival tax year is taxed as UK-resident at all.
- Overseas Workday Relief is a completely separate relief that can apply within the UK-resident part of your year (and future years), exempting the portion of your salary relating to days you were still working overseas even after becoming UK resident — if you meet the qualifying new resident test.
Someone who moves to the UK for a role that still has them travelling overseas regularly can have both apply in the same year: split year treatment excludes the pre-arrival period entirely, and OWR then exempts part of the post-arrival salary too, for genuinely overseas workdays.
Your first year is also year one of a four-year clock
If you qualify as a new resident, your arrival year is also the first of up to four tax years of FIG regime and OWR relief — not just a one-off transitional adjustment. That window is measured from your actual residence-start date, which is why getting the arrival-year mechanics right matters beyond just that single return. If you arrived before the FIG regime existed (it started 6 April 2025), your four-year window may already be partway used up — worth checking against the qualifying new resident test specifically.
Where FIG Tracker fits in
FIG Tracker tracks workdays from your actual arrival date forward — not the tax year boundary — including sourcing for any salary, RSU tranches, or bonuses whose relevant period starts before or straddles your move. See how OWR is actually calculated for the detail behind the sourcing itself.
FIG Tracker is a calculation aid, not tax advice. Always confirm which split year case applies to you, your eligibility, and your figures with a qualified tax advisor before filing with HMRC.