YA: Year of Assessment
The year your income is taxed in. YA 2027 taxes what you earned in 2026.
Singapore taxes income one year in arrears. The Year of Assessment (YA) is the year the tax is assessed, and it covers income from the year before: YA 2027 is for income earned from 1 Jan to 31 Dec 2026.
Most employees file between March and April; the e-filing deadline is 18 April. Many are on the No-Filing Service, where IRAS fills in the return from employer data, but you still need to claim reliefs that IRAS cannot see.
After filing you get a Notice of Assessment (NOA), your tax bill, usually by the end of September. Pay within 30 days or set up a GIRO plan to pay monthly.