Insights · Updated 2026-08

What is MCC 234? Mobile country code 234 explained (United Kingdom)

Mobile Country Code 234 is assigned to the United Kingdom, and a second code, 235, is reserved for it as well. Together they carry 77 MNC allocations in this dataset — from the four national networks down to dozens of MVNOs — of which 36 are operational. Here is what the code means and who sits behind it.

MCC 234 in one line

An MCC is the three-digit Mobile Country Code from ITU-T E.212 that identifies a SIM's home country (background: MCC, MNC and PLMN explained). It is a mobile-network identifier, not a dialling prefix — the UK dials with +44 but its networks key on 234. Add a Mobile Network Code (MNC) and you get a PLMN, the actual network address: 23415 = 234 + 15 is Vodafone UK.

234 vs 235: two codes, one country

The UK is one of a small number of countries with a spare MCC on hand. 234 is the working code where every consumer network lives; 235 is a secondary allocation and is barely used in practice: of its 14 records in this dataset only 1 is operational — a research/test network — with no retail brand of its own. The rest are unassigned or dormant placeholders. For practical lookups you can treat 234 as "the UK MCC" and only reach for 235 when a code genuinely begins with it.

The four host networks

Every UK mobile subscriber ultimately rides one of four physical networks. The figures below are pulled straight from the dataset for each network's primary PLMN, with published subscriber counts and market reach where available.

EE is owned by BT; O2 UK is part of the Telefónica-backed Virgin Media O2 venture; Three is run by Hutchison. Shares are each operator's published reach and are not mutually exclusive, since MVNO customers are counted under their host network too.

MVNOs share the host codes

Most recognisable UK brands are virtual operators (MVNOs) that carry their own MNC but run over one of the four hosts. The dataset lists many; a few operational examples:

• 23426 — Lycamobile
• 23454 — iD Mobile
• 23401 — Vectone Mobile
• 23425 — Truphone
• 23416 — Talk Talk
• 23400 — BT

Because an MVNO can hold its own PLMN, the network a phone reports is not always the brand on the bill. If you are trying to resolve an operator from a number rather than a live SIM, see how to find the mobile carrier from a phone number.

Reading a UK PLMN

UK MNCs are two digits, so a full PLMN is five characters — unlike the United States on MCC 310, where three-digit MNCs make six-character PLMNs. The leading zero matters: 10 is O2 and 01 is a different allocation entirely, so treat MNCs as strings, never integers.