I don’t see why it wouldn’t be. Professional caterers should have a cancellation policy in place that you would be made aware of before you sign a contract with them, but you should expect to pay some fees. Understand that these caterers prepare long before your wedding date and have incurred expenses already from purchasing ingredients, paying their staff, etc. Be very careful and double-check your event’s date first to avoid mixups. Look into the availability of your VIP guests to avoid moving or cancelling the service. You should also secure a venue first before booking a caterer.
If you’re searching for a reputable caterer in Dorset, I highly recommend this website. They cater to private parties such as weddings and birthdays as well as public events and festivals. I have hired them before, and their tapas are to die for! For small parties at home, they also do food deliveries without service.
There is no industry-wide guideline regarding cancellation with catering companies. As one would expect, it falls to individual companies to spell out their own policies.
So, in short, I would say that yes, it is possible to cancel with a professional catering company even after an agreement has been reached, but your specific case will depend on the exact company you choose to work with.
Usually, a professional catering company will state the exact timeline within which cancellation is possible. They will also state the fees that such cancellations will incur.
I have had to cancel a few times with Caterers Worthing, and one thing that is worth mentioning is that, naturally, companies don’t appreciate cancellations. So if you want to do it, make sure it’s for the right reasons, and you do it as far in advance as possible.