WhoIsCalling.me.uk

Number range

0300 123 xxxx

Ofcom’s records for the block of 10,000 numbers that start 0300123, and any numbers in it that we hold other information about.

What Ofcom’s records say

Allocated to
BT
The provider Ofcom gave the block to
Ofcom status
Allocated
Allocated on
26 March 2007
Area
Not linked to a place
Numbers in block
10,000 numbers
Number length
11 digits

Source: Ofcom numbering data, files published 7 October 2026, checked 13 October 2026

Ofcom has allocated this block of numbers to BT.

Ofcom allocates phone numbers to communications providers in blocks. The provider shown is the one Ofcom allocated this block to. It is not the person or business that called you, and the number may since have moved to a different network, because people can usually keep their number when they switch provider. Ofcom does not hold information about individual numbers.

Numbers in this range we know about

Numbers an organisation lists on its own website or in an official register, and numbers at least 3 visitors have reported.

Contains public sector information from NHS England (Organisation Data Service), "GP Practices (epraccur)" (13 October 2026), licensed under the Open Government Licence v3.0.

Contains public sector information from NHS England (Organisation Data Service), "NHS Trusts (etr)" (13 October 2026), licensed under the Open Government Licence v3.0.

Sources and checks

This page relies on:

Checked on 13 October 2026. Read how reports work. How we check our information. Spotted a mistake? Tell us and we will put it right.