Year of Assessment
'Year of Assessment' (YA) refers to the year in which income tax is calculated and charged. Each YA begins on 1 January and ends on 31 December.
Example: YA 2013 refers to the period 1 Jan 2012 to 31 Dec 2012.
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 2013 is 1 January 2012 to 31 December 2012.
If you receive business income, the basis period may be different if your accounts are made up to a date other than 31 December.
Example 1
Mr Tan has employment income from 1 January to 31 December 2012. This income is earned in the basis period from 1 January to 31 December 2012 and hence, it will be assessed in the Year of Assessment 2013.
Example 2
Mr Lee is a sole-proprietor. His financial year ends on 31 Mar 2012. His business income is earned in the basis period from 1 Apr 2011 to 31 Mar 2012 and hence, it will be assessed in the Year of Assessment 2013.
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 and shows the deductions 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:
a) trade income for the accounting year;
b) employment income (including additional wage supplement, bonus, allowances, benefits-in-kind, perquisites etc) from 1 January to 31 December of the YA and; or
c) other income such as rental income from 1 January to 31 December of the YA.
Personal reliefs
'Personal reliefs' are the deductions which help you to save tax. Find out more about reliefs.
Chargeable income
'Chargeable income' is your 'assessable income' after deducting 'personal reliefs'.
A typical tax computation looks like this:
