Which form do I need to start a divorce
You can apply for a divorce online at https://www.gov.uk/apply-for-divorce
If you have children you will also have to provide their names and dates of birth etc.
You will also need your original Marriage Certificate or a certified copy which you can obtain from the General Register Office (GRO)
You can also apply by post using Form D80B
You may also need to pay a court fee.
If you are claiming benefits or you are on a low income you may be able to avoid paying the court fee, but you will need to complete a Fees Exemption Form. You can apply online for help wth court fees - https://www.gov.uk/get-help-with-court-fees
Judicial Separation - an alternative to divorce