Search this and the honest short answer is: probably yes, unless a specific relief applies to you. UK tax residence, not the location of your desk on any given day, is what normally decides whether income is taxable here — and residence alone doesn't create any automatic exemption for days you happened to be working from abroad.
The default: worldwide income, once you're UK resident
Once you're UK tax resident — a status determined by the Statutory Residence Test, not by where you're physically sitting on a given workday — you're generally taxable on your worldwide income and gains, employment income included. That's true whether the work in question was done from a UK office, a hotel room in another country, or a client site overseas. Residence, not workday location, is the default trigger.
That surprises a lot of people who assume "I was working from outside the UK that day" is itself a reason the income isn't UK-taxable. It isn't, on its own.
The relief that changes this: Overseas Workday Relief
Overseas Workday Relief (OWR) is the specific mechanism that lets some people exclude part of their employment income from UK tax based on where the underlying duties were performed. It isn't a general rule for anyone who travels for work — it's available only to people who meet the FIG regime's qualifying new resident test: broadly, becoming UK resident after 10 consecutive tax years of non-UK residence, for a window of up to four tax years.
If you qualify, the portion of your employment income relating to workdays where duties were genuinely performed outside the UK can be exempt from UK tax for those years — subject to a cap (the lower of 30% of qualifying income or £300,000, detailed here) and an active election that also affects your personal allowance.
What actually counts as an "overseas workday"
This is a separate question from whether you're UK resident at all — that determination uses its own day-counting rules, including a deeming rule that can inflate your UK day count past what a simple tally would suggest. Your OWR workday fraction is a different, later count: which of your actual working days involved duties performed outside the UK, used only to source how much of your income is exempt once residence is already established.
Where FIG Tracker fits in
If you think you might qualify, the mechanical part — tracking which workdays were genuinely overseas, sourcing RSU tranches and bonuses over their own periods, and applying the cap correctly — is what FIG Tracker is built to handle. See how OWR is actually calculated for the detail behind the numbers.
FIG Tracker is a calculation aid, not tax advice. Always confirm your residence status and eligibility with a qualified tax advisor before relying on any of this for a return.