The minimum age to marry in England and Wales is to be raised from 16 to 18.
The Bill proposing the change was put forward by Conservative MP Pauline Latham last year and has now been passed by the House of Lords with support from both the government and opposition parties. It is expected to receive Royal Assent and be enshrined in law later this week.
Under the current law, individuals are allowed to get married at the age of 16, provided they have parental consent.
Campaigners have pushed for a change in the law to prevent girls being coerced into arranged marriages.
Marriage of a child is illegal for both registered and unregistered ceremonies.
The new law creates an offence for underage marriage “whether or not it is committed in England and Wales,” suggesting it will be illegal to take under 18s out of the country to get married.
In both Scotland and Northern Ireland, the legal marriage age remains 16 with parental consent.