- The Commissioner of Oath is required for a document that is used in Singapore. A Christian used the word Oath while a non-Christian use the word Affirm. The process is simpler and the cost is lower.
- A Notary Public is required for a document that is used outside Singapore. In some cases, a seal has to be affixed. It is more costly to have a document certified by a Notary Public.
A lawyer can be appointed by the court to be a Commissioner of Oath or a Notary Public after being in public practice for 5 to 10 years.