Where can I buy I/D tags for my crate, I believe it is a requirement nowadays.

i have seen people using postage lables you tie them on on to cage or id lables off suitcases

IDK but why not use a case label and insert something like a business card, or other, for details?

I don't know about I/D needed to be on crates to be honest.

It's a kennel club requirement. It's to be able to contact you if your dog is distressed etc. When left unattended. I would never dream of leaving mine without getting someone to keep an eye on but it must have happened to introduce the rule.

think it was introced about 4yrs ago i think i may be wrong
same her i never leave mine alone same with horses someone stayed with them at all times
its just comomon sense
when i had car i left my detiles up on front window at shows if one off dogs was left in car for 5im