Which company owns MAC address prefix 00:40:9E?

MAC address prefix 00:40:9E is registered to Concurrent Technologies Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:40:9E has a network interface built by Concurrent Technologies Ltd..

What is the OUI 00:40:9E?

00:40:9E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Concurrent Technologies Ltd.. It covers every address from 00:40:9E:00:00:00 to 00:40:9E:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-40-9E.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:40:9E:00:00:00 that is 00:40:9E — 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 Concurrent Technologies Ltd. located?

Concurrent Technologies Ltd. is listed at 4 Gilberd Court, Newcomen Way Colchester GB CO4 9WN in the IEEE OUI registry entry for 00:40:9E. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Concurrent Technologies Ltd.

MAC address prefix 00:40:9E is registered to Concurrent Technologies Ltd. in the IEEE OUI registry. Any device whose MAC address begins with 00:40:9E has a network interface built by Concurrent Technologies 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 00:40:9E:00:00:00 to 00:40:9E:FF:FF:FF.

OUI prefix: 00:40:9E
Hyphen form: 00-40-9E
MAC range: 00:40:9E:00:00:00 – 00:40:9E:FF:FF:FF
Addresses in block: 16,777,216
Organization: Concurrent Technologies Ltd.
Address: 4 Gilberd Court, Newcomen Way Colchester GB CO4 9WN
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 (3)

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 "CONCURRENT TECHNOLOGIES LTD."
archived source →
2023-07-11Renamed from "CONCURRENT TECHNOLOGIES LTD." to "Concurrent Technologies Ltd."
archived source →
2026-07-17Assigned to "Concurrent Technologies Ltd."

Nearby in the registry

The prefixes assigned immediately before and after 00:40:9E:

FAQ

Which company owns MAC address prefix 00:40:9E?: MAC address prefix 00:40:9E is registered to Concurrent Technologies Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:40:9E has a network interface built by Concurrent Technologies Ltd..
What is the OUI 00:40:9E?: 00:40:9E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Concurrent Technologies Ltd.. It covers every address from 00:40:9E:00:00:00 to 00:40:9E:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-40-9E.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:40:9E:00:00:00 that is 00:40:9E — 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 Concurrent Technologies Ltd. located?: Concurrent Technologies Ltd. is listed at 4 Gilberd Court, Newcomen Way Colchester GB CO4 9WN in the IEEE OUI registry entry for 00:40:9E. This is the address the organization registered with the IEEE, which may differ from its current operating address.