Range Holder vs current provider explained

If you've used our lookup, you've seen a field labelled Range Holder. It's the most accurate single piece of UK caller-identification data available to consumers — and also one of the most misunderstood. This guide explains what it is, what it isn't, and how to use it sensibly.

#What 'Range Holder' actually means

Ofcom allocates blocks of UK numbers — usually in 1,000-number or 10,000-number chunks — to communications providers (CPs). BT, Virgin Media O2, Sky, Vodafone, Gamma, TalkTalk, Three, Magrathea, Daisy, Voicehost and many others. The provider that originally received the block is recorded as the Range Holder, and that designation never changes — even if the customer who actually uses the number later ports it to a completely different network.

All of this is published by Ofcom in the National Telephone Numbering Plan and the weekly Numbering Data ZIP. We ingest both — see how Ofcom numbering works for the gritty detail.

#Why the Range Holder isn't always the network on your caller ID

When a UK number is ported, the underlying carrier swaps but the Range Holder doesn't. So if your bank ported its 0345 numbers from BT to Sky in 2018, Ofcom *still* lists BT as the Range Holder. Caller ID may show whichever network the call passed through last, the porting carrier, the originating carrier, or — in scams — a spoofed value entirely.

#How to use Range Holder data sensibly

• Confirms whether a number is Allocated, Free, Reserved, Protected or Recovered. A 'Free' or 'Reserved' number that is calling you should be treated with high suspicion.
• Gives the number's likely industry context (e.g. allocated to a wholesale SIP provider commonly used by call-centres).
• Does not tell you the call's actual purpose, current operator, or whether it's a scam.
• Pair it with the AI internet check on each lookup page for the fullest picture.

#What if the number isn't in Ofcom's data at all?

Three common explanations:

1. Brand-new block — Ofcom publishes weekly. New allocations may take up to seven days to appear.
2. Non-UK number presented as UK — caller-ID can be set to almost anything by the originating system.
3. Spoofed CLI — increasingly common in the UK; the number on your screen is not the line that placed the call.

On our lookup page, any of these three cases is labelled 'Not in current Ofcom data'.

#Bottom line

Range Holder data is excellent at pinpointing the type of number. For behavioural questions — 'is this number actually a scam?' — pair it with the AI internet check and the community scam databases we list in our who called me guide.