You may wish to make voluntary CPF contributions to build up your retirement savings. These contributions will be credited to your CPF Ordinary, Special and Medisave accounts according to the percentage allocated for your age and can be used for your housing and healthcare needs. You can make a one-time payment, or regular contributions deducted by GIRO to your CPF accounts.
While it is not compulsory for self-employed persons to contribute to the Ordinary and Special Accounts, you are encouraged to make voluntary contributions to all three accounts to build up your retirement savings. You will enjoy tax relief on your voluntary CPF contributions.
For more information on voluntary contributions, click here.
You may wish to visit IRAS website for more information on the prevailing tax rules.