Asking is allowed. Buying is not.
Asking a genuine customer for an honest review is normal and encouraged. Paying for reviews, writing them yourself, or offering a reward in exchange for a positive one is not — and in the UK it is a consumer-protection matter, not just a platform rule.
The Digital Markets, Competition and Consumers Act 2024 explicitly targets fake and incentivised reviews. Treat "just write us a five star and we will knock £10 off" as the legal risk it is.
The mechanics of actually getting them
Ask at the moment of relief — the job just finished and worked. Ask in person first, then send the link within the hour while goodwill is fresh.
Make it one tap. A short link straight to the review form, sent by text, converts far better than "search for us on Google and leave a review".
Answering the bad one
Reply once, briefly, without arguing, and move the detail offline: acknowledge, state the fact that matters, offer a way to fix it. You are not writing for the angry reviewer; you are writing for the next customer reading it.
A business with 40 reviews averaging 4.6 and thoughtful replies reads as more trustworthy than one with 12 flawless ones.