No: staying under 183 days does not guarantee non-residence. The jurisdiction, relevant year, personal ties and applicable exceptions matter. A day-count shortcut can miss a residence test. HMRC / GOV.UK IRS
Checked 2026-10-27. This is general education for individuals, not personal tax or legal advice. These UK and US examples are not a worldwide checklist.
Which year are you counting?
The UK tax year runs from 6 April to 5 April, so 2026/27 means 6 April 2026–5 April 2027. The US tests discussed here use the calendar year, 1 January–31 December. Do not transfer a threshold or day-count method between countries. HMRC / GOV.UK IRS
United Kingdom: fewer days can still mean residence
Individuals under the Statutory Residence Test
Spending 183 or more days in the UK in the tax year is an automatic UK residence test. Below that threshold, home, full-time work or sufficient ties can still matter. Apply the automatic overseas tests as well: UK residence requires an automatic UK test or sufficient ties and no automatic overseas test. The home and work tests have detailed conditions; owning a home alone is not the test. HMRC / GOV.UK
UK residents normally pay UK tax on worldwide income; non-residents pay UK tax on UK income, not foreign income. This is a general income-tax summary, not a calculation of every relief. Moving does not automatically qualify you for split-year treatment: its conditions must be met. HMRC / GOV.UK
United States: 183 can be a weighted total
Non-US citizens and the calendar year
The substantial presence test requires at least 31 days in the current year and a weighted total of at least 183: all current-year days + 1/3 of the preceding year's days + 1/6 of the days two years earlier. The green card test is a separate route to residence; this calculation is not a citizenship-tax rule. IRS IRS
Generally, any part of a US day counts. Qualifying transit, medical and exempt-individual days may be excluded, subject to conditions. “Exempt individual” concerns counting days, not blanket tax exemption; Form 8843 may be required. The closer-connection exception generally needs fewer than 183 actual days that year, a foreign tax home throughout the year, closer foreign ties and no disqualifying green-card steps or pending application. Special two-country and student rules exist. Form 8840 must be filed on time to claim the general exception, subject to limited late-filing relief. IRS IRS
Hypothetical: 130 days is not automatically safe
Assume a non-US citizen without a green card has 130 countable US days in each of 2024, 2025 and 2026. For 2026: 130 + 130/3 + 130/6 = 195. The 31-day minimum and weighted 183-day threshold are met, despite only 130 days in 2026. Check exclusions, closer connection and any applicable treaty before concluding the final status; this is not a tax-bill calculation. IRS IRS IRS
Two domestic residences, one treaty analysis
An individual can be resident under two countries' domestic laws. HMRC describes the usual OECD-model-style tie-breaker sequence: permanent home, centre of vital interests, habitual abode, nationality, then agreement between competent authorities if unresolved. The tests operate successively; consult the actual treaty, not a universal checklist. HMRC / GOV.UK
Treaty residence allocates residence for treaty purposes; it does not simply erase domestic filing duties. HMRC says a treaty non-resident can still have UK return obligations. For a dual-resident taxpayer claiming US treaty treatment as a resident of the other country, the IRS requires a timely Form 1040-NR with Form 8833. Treaty benefits depend on the income and treaty; some US states do not follow federal treaties. HMRC / GOV.UK IRS
What should you verify before relying on a day count?
Keep travel records, prior-year counts, home and family evidence, work details and filing deadlines. Fewer days may help meet one condition but leave another test or reporting duty intact. This article does not assess every country's rules, US state residence, elections or individual reliefs. Have a qualified adviser check the applicable year, domestic rules and treaty before acting.
For the broader distinction, read tax residency versus citizenship. For passport-related questions, see whether a second passport changes your taxes.