How to determine your legal name
The name that identifies a person for legal, administrative and other official purposes. A person’s first legal name generally is the name of the person that was given for the purpose of registration of the birth and which then appears on a birth certificate, but may change subsequently. Most jurisdictions require the use of a legal name for all legal and administrative purposes, and some jurisdictions permit or require a name change to be recorded at marriage. The legal name may need to be used on various government issued documents (e.g., a court order). The term is also used when an individual changes their first or full name, typically after reaching a certain legal age (usually 18 or over).