The short answer
In most places that license animal boarding, a cattery needs a licence from the local authority, and where you hold one it should be displayed prominently on the website with the licence number and any inspection or star rating. This is orientation rather than legal advice; your licensing authority is the authority on what you need and what you must show.
The website part is the bit catteries get wrong. The licence is usually framed on the office wall and missing from the site entirely, or hidden in the footer of a terms page.
Where catteries are licensed
The regime depends on where you work.
In England, cat boarding is a licensable activity under the 2018 animal activities licensing regulations, issued by the local council, with an inspection and a star rating attached. Scotland and Wales have their own arrangements. In the United States, boarding licences are state, county or city matters and vary a great deal. In Canada they are usually municipal, with animal care standards set provincially. In Australia, boarding establishments follow state codes of practice and generally register with the local council. Across the EU it is national, with countries such as Germany requiring a permit under animal welfare law for commercial boarding.
The common thread is that somebody inspects you and issues something with a number on it. That number is the most persuasive thing on your website, and it costs nothing to publish.
Why it matters more for a cattery than for a groomer
An owner choosing a groomer is buying an afternoon. An owner choosing a cattery is leaving a cat overnight for a fortnight with someone they have never met. They cannot supervise, they cannot check, and they feel guilty. A licence with an inspection rating is independent confirmation that somebody with authority has walked around your building and looked at your pens.
Where the rating is public, an owner can verify it. That is exactly why it converts.
Where it goes on the site
In the footer of every page, as a line of text: the licensing authority, the licence number, and the rating if you have one. Text, not an image, so it can be read out, copied and found in search.
On the about or premises page, with a short explanation of what the licence covers and what the inspection looked at. Two or three sentences. Owners do not know what a five star rating means until you tell them.
Near the booking button, as a single line of reassurance beside the pen photos and the reviews.
Linked to the public register where one exists, so the owner can check it themselves. A claim you invite people to verify is worth more than one they have to take on trust.
If the certificate is physical, photograph it in good light and put the image on the about page as well as the text. Keep the text version, because an image alone is invisible to search and to screen readers.
What else belongs beside it
Public liability and care, custody and control insurance, named insurer and cover in place. Any trade association membership. Staff qualifications or animal care training. Your emergency vet arrangement, which owners ask about constantly. And the Google reviews, which do a different job to the licence and work best next to it.
The rules about claiming
Do not state a licence, rating, qualification, membership or insurance you do not hold or that has lapsed. Consumer protection law in every market above treats that as a misleading claim, and it is also the sort of thing a competitor reports.
Put a reminder in your calendar for the renewal date, and update the site the week the new licence or rating arrives. A rating from three years ago on a live site is worse than no rating, because owners assume you are hiding the current one.
If your rating is not what you want
Publish it anyway, and publish what you have changed since. A cattery that shows a middling rating and a paragraph about the work done since the inspection reads as honest. A cattery that shows nothing reads as unlicensed, which is worse.
Where this sits
Licence and reviews displayed is one of the must-haves on every cattery website we build, and displayed credentials run through our pet business websites generally, from vet registrations to insurance. The packages are on pricing. The licence is already on your wall. Put the number where the owner deciding at ten at night can see it.