Which company owns MAC address prefix 3C:3B:4D?

MAC address prefix 3C:3B:4D is registered to Toyo Seisakusho Kaisha, Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:3B:4D has a network interface built by Toyo Seisakusho Kaisha, Limited.

What is the OUI 3C:3B:4D?

3C:3B:4D is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Toyo Seisakusho Kaisha, Limited. It covers every address from 3C:3B:4D:00:00:00 to 3C:3B:4D:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-3B-4D.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 3C:3B:4D:00:00:00 that is 3C:3B:4D — 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 Toyo Seisakusho Kaisha, Limited located?

Toyo Seisakusho Kaisha, Limited is listed at 2-4-6 Honjyo Higashi-Osaka Osaka JP 578-0953 in the IEEE OUI registry entry for 3C:3B:4D. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Toyo Seisakusho Kaisha, Limited

MAC address prefix 3C:3B:4D is registered to Toyo Seisakusho Kaisha, Limited in the IEEE OUI registry. Any device whose MAC address begins with 3C:3B:4D has a network interface built by Toyo Seisakusho Kaisha, Limited. 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 3C:3B:4D:00:00:00 to 3C:3B:4D:FF:FF:FF.

OUI prefix: 3C:3B:4D
Hyphen form: 3C-3B-4D
MAC range: 3C:3B:4D:00:00:00 – 3C:3B:4D:FF:FF:FF
Addresses in block: 16,777,216
Organization: Toyo Seisakusho Kaisha, Limited
Address: 2-4-6 Honjyo Higashi-Osaka Osaka JP 578-0953
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.

2023-07-11Assigned to "Toyo Seisakusho Kaisha, Limited"
archived source →
2026-07-17Assigned to "Toyo Seisakusho Kaisha, Limited"

Nearby in the registry

The prefixes assigned immediately before and after 3C:3B:4D:

FAQ

Which company owns MAC address prefix 3C:3B:4D?: MAC address prefix 3C:3B:4D is registered to Toyo Seisakusho Kaisha, Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:3B:4D has a network interface built by Toyo Seisakusho Kaisha, Limited.
What is the OUI 3C:3B:4D?: 3C:3B:4D is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Toyo Seisakusho Kaisha, Limited. It covers every address from 3C:3B:4D:00:00:00 to 3C:3B:4D:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-3B-4D.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 3C:3B:4D:00:00:00 that is 3C:3B:4D — 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 Toyo Seisakusho Kaisha, Limited located?: Toyo Seisakusho Kaisha, Limited is listed at 2-4-6 Honjyo Higashi-Osaka Osaka JP 578-0953 in the IEEE OUI registry entry for 3C:3B:4D. This is the address the organization registered with the IEEE, which may differ from its current operating address.