The short answer
Dog daycare, boarding kennels and home boarding are licensed activities in most countries, usually by the local authority or council, and often with an inspection or star rating attached. The licence number and the rating should be on the website where owners look, not buried in the terms. Displaying it is frequently a condition of the licence itself, and it is also the single strongest trust signal a kennel has.
This is orientation rather than legal advice. Your licensing authority is the authority on what you must show and where.
Who licenses you
England. The Animal Welfare (Licensing of Activities Involving Animals) Regulations 2018 license dog boarding in kennels, home boarding, day care for dogs, and selling and breeding. The local authority issues the licence with a star rating from one to five, and licence holders are generally required to display the licence and to include the licence number in advertising, including online. Scotland and Wales run their own arrangements with similar effect.
United States. Mostly state, county or city. Kennel and boarding licences vary widely in what they require, and some jurisdictions require the licence number in advertising. Federal Animal Welfare Act licensing through the USDA applies mainly to breeders, dealers and exhibitors rather than a typical daycare.
Canada. Usually municipal kennel licensing, with animal care standards set provincially. Display requirements vary by municipality.
Australia. State and territory codes of practice for boarding establishments, with registration through the local council. Victoria and New South Wales both publish a code.
European Union. National. Germany, for example, requires a permit under its animal welfare law for commercial boarding, and the permit is commonly shown. Other member states register boarding differently.
Check your own authority's conditions before you write anything on the page, because the wording they expect is sometimes specified.
Where it goes on the site
Three places.
The footer, on every page. Licence number, issuing authority, and the rating. One line. This is what satisfies a display condition and what a careful owner scrolls to find.
The facilities or about page. The same details with a sentence of context: what the licence covers, when it was last inspected, what the rating means. Most owners do not know that a five star rating exists or that it is awarded by the council, so tell them.
Near the booking button. A short line, because the moment before booking is the moment doubt appears.
If your authority publishes a public register, link to your entry. A link to an independent record is worth more than a number typed on your own page.
Show the rating, and show it honestly
A five star rating is your best asset and it should be visible above the fold on the home page. A three star rating is not a reason to hide the number. Owners can look you up, and finding a rating you concealed is worse than finding one you explained. Where a rating reflects something you have since fixed, say what changed and when the next inspection is due.
Never display a rating, licence, membership or accreditation you do not hold. That is misleading advertising in every jurisdiction listed above, and it is the fastest way to lose a licence you do hold.
What else the licence touches on the website
Licence conditions often set the things your site is already describing: dogs per handler, space per dog, staffing overnight, isolation facilities, the vaccination policy, record keeping. Where a condition sets a number, the number on your daily routine page and requirements page should match it. An inspector reading your website should recognise the business.
Insurance is separate from licensing and belongs beside it: public liability, care custody and control, and the cover you hold for veterinary treatment.
Home boarders and franchisees
Home boarding is licensed too in many places, and often to the individual host rather than the business. If you run a network of hosts, say on the site how each host is licensed and inspected, because owners assume a home boarding network is less regulated than a kennel and it usually is not.
The other rules that apply
Licensing is one layer. The rest of the website answers to consumer law on prices and cancellation, privacy law for the owner data and vaccination records your booking platform holds, company details, marketing consent for reminder emails and texts, and accessibility. Those differ by country too.
Where this sits
Licence, inspection rating and insurance displayed where owners look is one of the six must-haves on the dog daycare and boarding websites we build. Licensing is the point where this kind of business is more regulated than most of the pet businesses around it, and the businesses that treat the rating as marketing rather than paperwork get more from it than any strapline they could write.