Self Assessment is the UK\'s primary tax instrument for any individual whose income is not collected from a single employer under PAYE. It applies to freelancers, landlords, company directors, and anyone with foreign income.
Who Must File?
- Self-employed with income above £1,000.
- Company directors receiving dividends.
- Landlords with rental income above £2,500.
- Income above £100,000.
- UK residents with foreign income (including Turkish rental property).
Critical Dates
- 5 April: fiscal year end.
- 31 October: paper return deadline.
- 31 January: online return and tax payment deadline.
- 31 July: second Payment on Account.
Making Tax Digital (MTD)
From April 2026, self-employed individuals with income above £50,000 are mandated into MTD: quarterly digital updates plus year-end return. The threshold drops to £30,000 from 2027.
Non-Residents
A Turkish resident earning UK rental income or dividends can receive rent gross under the Non-Resident Landlord (NRL) scheme, but an annual Self Assessment return remains mandatory. Tax paid in the UK is creditable in Turkey.
Common Errors
The most frequent error: assuming UK rental income alone triggers UK residence. The Statutory Residence Test is day-count based; property ownership by itself does not create residence. Second error: insufficient documentation of allowable expenses — on HMRC enquiry, undocumented claims are disallowed.