Income Tax Glossary

Glossary of terms relating to individual income tax such as Year of Assessment, Notice of Assessment, and Assessable Income.

Year of Assessment

'Year of Assessment' (YA) refers to the year in which income tax is calculated and charged. The assessment is for the income earned in the preceding year, starting on 1 Jan and ending on 31 Dec.

Example: For YA 2020, the assessment is for income earned from 1 Jan 2019 to 31 Dec 2019.

Basis period

'Basis period' refers to the period of income relevant to the YA. The basis period for a YA is the year preceding that YA.

Example: The basis period for YA 2020 is 1 Jan 2019 to 31 Dec 2019.

If you receive business income, the basis period may be different if your accounts are made up to a date other than 31 Dec.

Example 1: Employment Income

Mr Tan has employment income from 1 Jan 2019 to 31 Dec 2019. This income is earned in the basis period from 1 Jan to 31 Dec 2019 and hence, it will be assessed in the Year of Assessment (YA) 2020.

Example 2: Business Income

Mr Lee is a sole-proprietor. His business financial year ends on 31 Mar 2019. His business income is earned in the basis period from 1 Apr 2018 to 31 Mar 2019 and hence, it will be assessed in the YA 2020.

Notice of Assessment (NOA)

'Notice of Assessment' refers to your tax bill. It shows the types of income and amount of income subject to tax, calculates the tax amount you need to pay, the deductions (e.g. reliefs, expenses, donations) given, as well as the credit balance to be refunded to you.

Find out more about how to read your tax bill.

Assessable income

'Assessable income' is your total income after deducting allowable expenses and approved donations. Total income includes:

  1. trade income for the accounting year;
  2. employment income; and
  3. other income such as rental income, royalty income etc.


'Employment' income shown is the net amount after deducting your employment expenses. 
'Property' income shown is the net rental income after deducting your rental expenses.

Personal reliefs

'Personal reliefs' are deductions which can help you save tax. These are allowable if:

• You are a Singapore tax resident; and
• You meet the qualifying conditions.

Find out more about personal reliefs.


Chargeable income

'Chargeable income' is your 'assessable income' after deducting 'personal reliefs'. 

Singapore's personal income tax rates for resident taxpayers are progressive. This means that the higher the earnings, the higher the marginal tax rate. Please refer to the links below for more information:

Resident Tax Rates

How to Calculate Your Tax



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