A Taxpayer Registration Number (TRN) is a unique nine digit identification number assigned to each individual taxpayer. A TRN is needed when you start to work, when you open a bank account, when applying for HEART Trust/NTA Programmes, and to do any form of business with Tax Administration Jamaica (Tax Office), such as applying for a Driver's Licence. This application validates a number against the rules for a valid Jamaican TRN.