For wages to be classified as Ordinary Wages (OW) for the month, it must satisfy both conditions below:

The wages are due or granted wholly or exclusively in respect of an employee’s employment during that month; and

The wages for that month are payable by 14th of the following month.

Wages which are not classified as OW will be Additional Wages (AW) for the month.

The overtime (OT) pay has to be apportioned to OT performed in each calendar month before classification. Please see examples below.

Example 1: OT performed in a calendar month

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Example 2: OT performed across two calendar months, e.g. 25 Mar to 24 Apr

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*As CPF contribution is computed based on calendar month, the OT component from 25 Mar to 30 Mar can only be classified as OW if it is payable by 14th of the month following Mar i.e. 14 Apr. Since the OT pay is only payable on 30 Apr, it does not fulfil the second condition for it to be classified as OW.

Source: CPF Board - Overtime