CPF Submission Number is the number you use to transact with CPF Board e.g. making CPF payments, paying foreign worker levies, SHG contributions and making any request relating to employer matters. In essence, CSN comprises your Unique Entity Number (UEN) + CPF Payment Code.
For example, the number should look like "Unique Entity Number (UEN) + CPF Payment Code = xxxxxxxxxx-PTE-01.
For individuals (employers trading under own names i.e. hiring local employees such as a personal driver, gardener and local domestic worker), the CSN is the 'NRIC/Foreign Identification Number (FIN) + CPF Payment Code'.
For other individuals hiring foreign domestic workers or individuals who are self-employed, the CSN is the individual's NRIC/FIN.
If you have not registered your company with CPF yet, don't worry. You can head over to this link: https://www.cpf.gov.sg/Employers/EmployerGuides/employer-guides/paying-cpf-contributions/cpf-e-submission. Scroll down until you see Apply section and click on Apply online.
The link will redirect you to a separate page that requires you to sign in with your CorpPass (how to sign up for CorpPass?). Thereafter, you can follow the steps accordingly to register.
Once you have obtained your CPF Submission Number, head over to Profiles > Company Details > Payroll Details and key in the number in the field. 😁