Your checklist should include checking whether the adviser is regulated by the Solicitors Regulation Authority (SRA) or the Immigration Advice Authority (IAA), and whether they have experience with your visa route. Ask for a written estimate of fees, what the service covers, likely timescales, and any extra costs, then confirm who will handle your case. Check their complaints procedure and make sure you receive clear terms of business and a list of documents needed. You can verify the latest visa requirements on GOV.UK and seek advice from a regulated professional about your circumstances.