Insights · Updated 2026-08

What is MCC 310? Mobile country code 310 explained (United States)

Mobile Country Code 310 is one of several codes assigned to the United States. Unlike most countries, which manage on a single MCC, the US spans a whole block — 310 through 316 — because it long ago ran out of room for new operators under one code. Across those seven MCCs the dataset lists 486 MNC allocations, of which 183 are currently operational.

MCC 310 in one line

An MCC is the three-digit Mobile Country Code from ITU-T E.212 that opens every SIM's identity (see MCC, MNC and PLMN explained). It is not the international dialling code: the US dials with +1, but its mobile networks are keyed on 310 and its siblings. A network is then pinned down by adding a Mobile Network Code (MNC) to form a PLMN, for example 310260 = 310 + 260 for T-Mobile.

Why the US uses seven MCCs (310–316)

Most countries fit under one MCC because a two-digit MNC gives up to 100 slots — plenty for a handful of national carriers plus MVNOs. The United States is different. It has hundreds of licensed operators, regional carriers and virtual networks, so a single 100-slot code was never going to hold them. The answer was to allocate a contiguous block: 310, 311, 312, 313, 314, 315 and 316. In this dataset alone the block carries 99 distinct network brands.

The US also leans on three-digit MNCs. Where the Czech Republic writes O2 as 02 (a two-digit MNC, PLMN 23002), a US PLMN such as 311480 uses the three-digit MNC 480. That makes many US PLMNs six characters long instead of five, and it is why a single operator can hold dozens of codes — Verizon alone accounts for 42 allocations across the block for its various network partitions and IoT ranges.

Major US operators on MCC 310–316

The market is dominated by three national carriers. The table below is computed from the dataset — one representative PLMN per brand, with the number of MNC allocations that brand holds across 310–316, and published subscriber figures where available. Subscriber counts and market share reflect each operator's most recent reported numbers.

"MNC codes" counts every MNC allocation the brand holds across 310–316 in the dataset, operational or otherwise. Market share is the operator's published reach of the national subscriber base. Explore every row in the registry or fetch it programmatically from the free API.

Reading a US PLMN

In an IMSI, these six digits sit at the front, before the subscriber's MSIN — see IMSI explained. Note the leading zero in 030: MNCs are strings, and 030 is not the same slot as 30 would be. Always compare codes as text, never as integers.