SET5.10 What evidence is required that any previous marriage/civil partnership or similar relationship has permanently broken down?
Each of the parties to the unmarried or same-sex partnership is required to provide evidence regarding any previous marital or other relationship akin to marriage / civil partnership they have had. They should be asked to specify how long ago the previous relationship was terminated, either by divorce / dissolved civil partnership, by separation or by death:
Widowed person: death certificate of the late spouse.
Surviving civil partner: death certificate of the deceased civil partner.
Divorced person: evidence of divorce eg a divorce certificate. NB for the UK this is a decree absolute divorce certificate - this is stated on the order from the Family Court. A person is not legally divorced until the decree absolute is issued. A decree nisi is not acceptable evidence. See SET13 - Overseas divorces.
Dissolved civil partnership: evidence of the dissolution eg dissolution certificate.
http://www.ukvisas.gov.uk/en/ecg/set...esex#560781082
also you might find this useful
http://www.uklgig.org.uk/uprule.htm