A double-barrelled surname — two surnames joined by a hyphen — is created and formalised by deed poll in the UK. Whether you are combining your surname with a partner's after marriage, honouring two family names, or simply prefer the sound of a hyphenated name, the process is the same: a deed poll states the name you are abandoning and the double-barrelled name you are adopting. Once signed and witnessed, it is a legally valid document accepted by every UK organisation.
It is important to understand that a marriage certificate alone does not entitle you to a double-barrelled name. The marriage certificate only covers taking your spouse's surname as a direct replacement. If you want to combine both surnames — say, Smith-Jones or Patel-Williams — you need a deed poll, regardless of your marital status. Both partners can each use their own deed poll to adopt the same combined surname, meaning you can share a new hyphenated name without either of you giving up your own.
There is no restriction on which two surnames you combine, and the hyphenated name does not need to relate to any existing family name. You simply declare the combined name on the deed poll, sign it in front of two witnesses, and it becomes your legal name. This service generates a correctly worded deed poll for a double-barrelled name change — accepted at the Passport Office, DVLA, banks, and everywhere else in the UK.