An Unsecured Promissory Note is one in which the borrower provides only a written promise to repay a loan. A Promissory Note becomes secured when the borrower provides collateral in exchange for the loan. The lender can then sell the collateral to recoup the borrowed money if the borrower fails to repay the loan. However, some types of collateral (e.g., intellectual property rights) require registration under the Companies Act by companies in Singapore. Failing to register this collateral within 30 days of creating the agreement will make gaining possession of the collateral unenforceable. Check Section 131(3) of the Companies Act to see if you need to register the collateral in your Promissory Note. Both secured and unsecured Promissory Notes are legally binding.