It’s perfectly possible to apply for a UK visa on your own, and in fact, the system is set up for individuals to apply directly. Each visa is governed by published immigration law and has supporting information available for applicants. However, unless you’re familiar with immigration law, the application of this in practice, and the rigorous assessment processes of UK Visas and Immigration (UKVI), then you could run into trouble.
While the process is set up for individuals to apply, it’s not a forgiving process. Failure to supply the correct information and documents leads to an instant refusal. This means the loss of the government fees paid (which can run into thousands of pounds), but also potentially the loss of your chance to come to the UK or remain in the UK.
Given the limitations on when you can apply for most visas, it’s a high-stakes game to apply without being 100% confident of a successful outcome. First Migrations expertise and service can give you this confidence.