Our cats are fairly young and had never travelled before so we went to the vets in April and arranged for them to have Pet Passports. All went well, they had already been microchipped and vaccinated, they just needed the rabies injection and the actual Pet Passports themselves. The vet did all this for us and double-checked the microchip reading which he entered into the passport. All was done and I knew that 3 weeks later we could go away.
We went away at the beginning of June, and returned to Dunkerque to get the car ferry home at the beginning of July. When we got to Passport control we had to scan the cats’ microchips to make sure they tallied with the Passports we had. Tilly was fine, no problem. Domino however had a microchip that didn’t match what was written in his passport. The vet had written the number down incorrectly, he had missed out a digit. The customs official was naturally concerned about this and was well within his rights to refuse us entry back to the UK. Luckily I had the original microchip record plus the official understood and could clearly see that it was a simple mistake and let us through. We were able to catch the ferry home as planned but it could easily have turned out to be a very expensive nightmare for us.
The moral of the story is: double check all your documentation yourself, even if you watch someone else do it first, make sure you do it again to be sure!