Testimonials sit on nearly every business website and do less work than owners expect.
The reason is structural. A quote on your own site was selected by you, from material you control, and edited by you. A reader knows that, even if they never articulate it, and they discount it accordingly.
That does not make testimonials worthless. It makes them a supporting element rather than the main proof, and it changes how they should be handled.
Why a review beats a testimonial
A review sits somewhere you do not control, under a name, at a place a reader can go and check. A testimonial sits on your page under whatever attribution you chose to give it.
Same words, very different weight.
If you have both, point at the review record and let the testimonials support it. If you have only testimonials, the first useful move is building a review record.
If you use them, use them properly
Get permission first. A comment made to you in conversation, or in a private message, is not published material. Ask before it goes up, and say where it will appear.
Attribute as fully as they allow. A full name is better than a first name. A first name and a town is better than an initial. An unattributed quote is read as invented, whether or not it is.
Do not edit the meaning. Trimming for length is fine if the sense is unchanged. Removing a qualification, combining two comments, or tidying somebody's words into a better sales sentence is not.
Date them. A quote with no date is read as current indefinitely. If your best testimonial is several years old, the date is doing you a service by being honest about that.
Keep the original. Whatever they actually sent or said, kept with the permission note.
What not to do
Do not write them. This should not need saying and it happens constantly. A written-for-you testimonial is a fabricated customer statement, and the ones that read best are usually the most obviously fake.
Do not use a stock photograph beside a real quote. A real customer with somebody else's face attached turns honest material into something dishonest.
Do not use initials to obscure that you only have a handful. Four quotes attributed to initials read worse than one attributed to a full name.
Do not move a review onto your page and treat it as a testimonial without saying where it came from. Say which platform it is from, so a reader who wants to check can.
Do not lead with an outcome claim. A quote saying business doubled is a result claim, and it needs the same substantiation any other result claim needs: what was counted, over what period, from what record. Without that, it should not be on the page even in somebody else's words.
The last point is the important one
A claim does not become safe because a customer made it.
If a testimonial asserts a business outcome, and it is published on your site to persuade people to buy, then it functions as your claim. The backing for it lands on you.
Quotes about what the work was like, how the process went, and how people were treated do not have this problem, and they are more persuasive anyway because they describe something the reader can imagine.
What to use instead
The strongest proof available to most local businesses is not a quote at all.
Photographs of real work, taken properly. A described job with specifics. A review record a reader can visit. A credential they can verify. Something dated.
Those are checkable, and checkable is the whole game.
Where to start
Look at every testimonial on your site and ask three things: did the person agree to it being there, is it attributed as fully as they allowed, and does it claim a business outcome.
Anything that fails the first two gets fixed or removed. Anything that fails the third comes down.
If you want an outside read on how your site's proof currently holds up, the free check covers your website, your Google profile, your search results, and your reviews. Nothing is logged into or changed, and the findings are yours to keep.