People in England talk differently.
I'd kinda know that, what with being British and all ;)
Instead of asking for your "numbers" they'll ask for your "numerics".
You know some weird-arse Brits, then! I've never heard anyone say "numerics". You can say "it was numeric", since "it was numbers" makes you sound stupid.
IP addresses are numeric in as much as they are made of numbers, but that is a description of the format of the IP address and not an alternative word to be used in place of "address". Alternatively you'd say "a numeric IP address", but given that you can't have "a textual IP address" then it is a bit redundant (you can have hex encoding, but that's just a different numeric base).
"IP holder" was partly a confusion in the context about IP - they're talking about copyright, so "IP holder" normally means "Intellectual Property owner", or "the litigious bugger who would rather sue than modernise his ways" - but also just an oddity in the language - there is no property for you to hold or lease. You can be a leasee or assignee of an IP address, but "IP holder" just jarred a bit.