Which company owns MAC address prefix 04:2F:56?

MAC address prefix 04:2F:56 is registered to ATOCS (Shenzhen) LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:2F:56 has a network interface built by ATOCS (Shenzhen) LTD.

What is the OUI 04:2F:56?

04:2F:56 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ATOCS (Shenzhen) LTD. It covers every address from 04:2F:56:00:00:00 to 04:2F:56:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-2F-56.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 04:2F:56:00:00:00 that is 04:2F:56 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.

Where is ATOCS (Shenzhen) LTD located?

ATOCS (Shenzhen) LTD is listed at 4/F., Building 10, Tongfuyu Industry Zone, Xili Town, Shenzhen CN in the IEEE OUI registry entry for 04:2F:56. This is the address the organization registered with the IEEE, which may differ from its current operating address.

ATOCS (Shenzhen) LTD

MAC address prefix 04:2F:56 is registered to ATOCS (Shenzhen) LTD in the IEEE OUI registry. Any device whose MAC address begins with 04:2F:56 has a network interface built by ATOCS (Shenzhen) LTD. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address — it covers every MAC from 04:2F:56:00:00:00 to 04:2F:56:FF:FF:FF.

OUI prefix: 04:2F:56
Hyphen form: 04-2F-56
MAC range: 04:2F:56:00:00:00 – 04:2F:56:FF:FF:FF
Addresses in block: 16,777,216
Organization: ATOCS (Shenzhen) LTD
Address: 4/F., Building 10, Tongfuyu Industry Zone, Xili Town, Shenzhen CN
Source: IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2016-07-29Assigned to "ATOCS (Shenzhen) LTD"
archived source →
2026-07-17Assigned to "ATOCS (Shenzhen) LTD"

Nearby in the registry

The prefixes assigned immediately before and after 04:2F:56:

FAQ

Which company owns MAC address prefix 04:2F:56?: MAC address prefix 04:2F:56 is registered to ATOCS (Shenzhen) LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:2F:56 has a network interface built by ATOCS (Shenzhen) LTD.
What is the OUI 04:2F:56?: 04:2F:56 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ATOCS (Shenzhen) LTD. It covers every address from 04:2F:56:00:00:00 to 04:2F:56:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-2F-56.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 04:2F:56:00:00:00 that is 04:2F:56 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.
Where is ATOCS (Shenzhen) LTD located?: ATOCS (Shenzhen) LTD is listed at 4/F., Building 10, Tongfuyu Industry Zone, Xili Town, Shenzhen CN in the IEEE OUI registry entry for 04:2F:56. This is the address the organization registered with the IEEE, which may differ from its current operating address.