Start with the specific visa route and check the latest requirements on the relevant GOV.UK page, as documents vary by visa type and personal circumstances. Your checklist may include a valid passport, completed online form, application fee, biometric appointment, proof of finances, accommodation details, sponsorship evidence and certified translations where required. Some applicants may also need a tuberculosis test, criminal record certificate or evidence of a genuine relationship. Before submitting, check that dates and information are consistent; for complex cases, consider advice from a solicitor regulated by the SRA or an authorised immigration adviser.