Worth flagging early: any service that offers to "do the literature review" for you is stepping onto thin ice. UK universities treat contract cheating seriously, and a proposal that gets written for you tends to unravel at the viva or when the supervisor asks a follow-up question you can't answer. So the useful question is not "who can write it" but "what does good support actually look like".
The part most people struggle with For business and management students it's almost always the research question. Topics start far too broad ("the impact of social media on SMEs") and the student ends up with something that would take a funded research team three years. Good support pushes back hard on scope until the question is answerable with the data, time and access a single student realistically has. A close second is methodology, particularly justifying why interviews rather than a survey, or why a case study rather than a comparison.
What genuinely useful support does - Asks awkward questions rather than supplying answers
- Helps you map what already exists so you can spot the gap, without summarising the papers for you
- Checks the proposal against your department's marking criteria, which are usually published in the handbook
- Sanity-checks access: can you actually get twenty business owners to give you an hour each?
Most of this is available free. Every UK university has a study skills or academic writing centre, supervisors are paid to read drafts, and library staff will run a literature search session with you. Business school students also have a useful asset in this forum and others like it: owner-managers who will tell you bluntly whether your research question matters to anyone running a company.
If a paid service is the route, treat it like hiring any supplier. Ask who does the work, what qualifications they hold, and get in writing that they are providing feedback and coaching rather than finished text. If they won't commit to that, walk away.