Which company owns MAC address prefix 40:B3:CD?

MAC address prefix 40:B3:CD is registered to Chiyoda Electronics Co.,Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 40:B3:CD has a network interface built by Chiyoda Electronics Co.,Ltd..

What is the OUI 40:B3:CD?

40:B3:CD is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Chiyoda Electronics Co.,Ltd.. It covers every address from 40:B3:CD:00:00:00 to 40:B3:CD:FF:FF:FF, or 16,777,216 addresses in total. It is also written 40-B3-CD.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 40:B3:CD:00:00:00 that is 40:B3:CD — 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 Chiyoda Electronics Co.,Ltd. located?

Chiyoda Electronics Co.,Ltd. is listed at 1-3-11 Nishiki-cho Warabi Saitama JP in the IEEE OUI registry entry for 40:B3:CD. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Chiyoda Electronics Co.,Ltd.

MAC address prefix 40:B3:CD is registered to Chiyoda Electronics Co.,Ltd. in the IEEE OUI registry. Any device whose MAC address begins with 40:B3:CD has a network interface built by Chiyoda Electronics Co.,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 40:B3:CD:00:00:00 to 40:B3:CD:FF:FF:FF.

OUI prefix: 40:B3:CD
Hyphen form: 40-B3-CD
MAC range: 40:B3:CD:00:00:00 – 40:B3:CD:FF:FF:FF
Addresses in block: 16,777,216
Organization: Chiyoda Electronics Co.,Ltd.
Address: 1-3-11 Nishiki-cho Warabi Saitama JP
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 "Chiyoda Electronics Co.,Ltd."
archived source →
2026-07-17Assigned to "Chiyoda Electronics Co.,Ltd."

Nearby in the registry

The prefixes assigned immediately before and after 40:B3:CD:

FAQ

Which company owns MAC address prefix 40:B3:CD?: MAC address prefix 40:B3:CD is registered to Chiyoda Electronics Co.,Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 40:B3:CD has a network interface built by Chiyoda Electronics Co.,Ltd..
What is the OUI 40:B3:CD?: 40:B3:CD is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Chiyoda Electronics Co.,Ltd.. It covers every address from 40:B3:CD:00:00:00 to 40:B3:CD:FF:FF:FF, or 16,777,216 addresses in total. It is also written 40-B3-CD.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 40:B3:CD:00:00:00 that is 40:B3:CD — 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 Chiyoda Electronics Co.,Ltd. located?: Chiyoda Electronics Co.,Ltd. is listed at 1-3-11 Nishiki-cho Warabi Saitama JP in the IEEE OUI registry entry for 40:B3:CD. This is the address the organization registered with the IEEE, which may differ from its current operating address.