Can the provider supply you with testimonials of satisfied customers and evidence of the level of ongoing support on offer?
Do you want your website to be unique to you with a bespoke design or are you happy with a templated site?
Will you require ongoing assistance and fast responses from a local consultant or are you happy going through a call centre?
How many resources does the provider have? For example, do they have a team of UK based professional designers and developers?
Would you want a payment plan that allows you to earn immediately and support your cash flow, or would you want to pay all at once?
Is it important for you to rank well on Google? If so, does the provider offer the tools, training, and resources needed to achieve this?
Does your website need to look good on a mobile device, load quickly, and be easy navigable?