Which company owns MAC address prefix 9C:5E:73?

MAC address prefix 9C:5E:73 is registered to Calibre UK LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 9C:5E:73 has a network interface built by Calibre UK LTD.

What is the OUI 9C:5E:73?

9C:5E:73 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Calibre UK LTD. It covers every address from 9C:5E:73:00:00:00 to 9C:5E:73:FF:FF:FF, or 16,777,216 addresses in total. It is also written 9C-5E-73.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 9C:5E:73:00:00:00 that is 9C:5E:73 — 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 Calibre UK LTD located?

Calibre UK LTD is listed at Cornwall House Bradford West Yorkshire GB BD8 7JS in the IEEE OUI registry entry for 9C:5E:73. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Calibre UK LTD

MAC address prefix 9C:5E:73 is registered to Calibre UK LTD in the IEEE OUI registry. Any device whose MAC address begins with 9C:5E:73 has a network interface built by Calibre UK 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 9C:5E:73:00:00:00 to 9C:5E:73:FF:FF:FF.

OUI prefix: 9C:5E:73
Hyphen form: 9C-5E-73
MAC range: 9C:5E:73:00:00:00 – 9C:5E:73:FF:FF:FF
Addresses in block: 16,777,216
Organization: Calibre UK LTD
Address: Cornwall House Bradford West Yorkshire GB BD8 7JS
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 "Calibre UK LTD"
archived source →
2026-07-17Assigned to "Calibre UK LTD"

Nearby in the registry

The prefixes assigned immediately before and after 9C:5E:73:

FAQ

Which company owns MAC address prefix 9C:5E:73?: MAC address prefix 9C:5E:73 is registered to Calibre UK LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 9C:5E:73 has a network interface built by Calibre UK LTD.
What is the OUI 9C:5E:73?: 9C:5E:73 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Calibre UK LTD. It covers every address from 9C:5E:73:00:00:00 to 9C:5E:73:FF:FF:FF, or 16,777,216 addresses in total. It is also written 9C-5E-73.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 9C:5E:73:00:00:00 that is 9C:5E:73 — 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 Calibre UK LTD located?: Calibre UK LTD is listed at Cornwall House Bradford West Yorkshire GB BD8 7JS in the IEEE OUI registry entry for 9C:5E:73. This is the address the organization registered with the IEEE, which may differ from its current operating address.