SEO UK Based companies are the only way to get to Google page one. Using companies based outside of the UK will more than often result in getting your website sand boxed by Google.
Choose the SEO company carefully asking the SEO company about the techniques they use and select an SEO company that will be able to deliver Google Page One Results, On Page SEO and Backlinks that stay with High Page Authority. Most UK based companies can deliver this but there are many that out source the SEO.
White label work where an SEO compay out sources the work to another company means that you pay the privelage. The first thing you should do is look in Google for terms like “UK Based SEO Company” and “if you are located in a specific are for example Birmingham search “Birmingham SEO Company“.
Think about how the SEO company will win work, and then see if they can achieve the results for there own website.