
The problem is that paperwork is checked at the port in France etc, and they simply check the dates tally on the passport, but don't make sure the dates tally with the obvious age of the puppies (though a member of the general public may not be able to recognise the difference between a 16 week puppy and one younger.
By 16 weeks if the baby teeth are not being lost then they will be extremely gappy and small looking.
Most often the checking staff do no actually handle the animal asking the owner to scan and they just check chip against paperwork.
Where the authorities should stop them is at Dover, put them in Quarantine and charge the traffickers the quarantine fees will soon make them find it unprofitable.
With these particular pups if it is obvious they re under 16 weeks of age then they should go into Quarantine as they are here ILLEGALLY!!!!
Of course nothing to stop them bringing in pups that are over 16 weeks,b but they have lost most of their cuteness factor, and of course 8 - 16 weeks of food usually about half as much again as an adult eats will seriously impact on breeders and traffickers profit margins :)