Compare providers by checking whether they are regulated, such as an immigration adviser authorised by the Immigration Advice Authority (IAA) or a solicitor regulated by the SRA. Ask about their experience with your visa route, exactly what the fee includes, likely timescales and any extra charges for appeals or further work. You can also compare independent reviews, but do not rely on testimonials alone. For current eligibility rules and application fees, check GOV.UK, and consider professional advice if your case involves refusal, overstaying or complicated family circumstances.