This depends on how important the outcome of the application is and whether you can take the risk of having the application refused on the first attempt.  Our immigration lawyers specialise in UK visa applications and know exactly how to prepare a successful application, what documents to include and what information to include in the cover letter.  Our 100% success rate with applications which do not involve exercise of discretion means that we expect a successful outcome in every application we make unless there is a reason why it may fall for refusal. We cannot guarantee an outcome as a refusal may also be a result of a mistake on the part of the Home Office, but we work very carefully to preempt any mistakes and explain in the cover letter how the application should be assessed. We can challenge a refusal if it was a result of an error.