Which company owns MAC address prefix 00:40:84?

MAC address prefix 00:40:84 is registered to Honeywell in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:40:84 has a network interface built by Honeywell.

What is the OUI 00:40:84?

00:40:84 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honeywell. It covers every address from 00:40:84:00:00:00 to 00:40:84:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-40-84.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:40:84:00:00:00 that is 00:40:84 — 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 Honeywell located?

Honeywell is listed at 512 Virginia Dr Ste A Fort Washington PA US 19034 in the IEEE OUI registry entry for 00:40:84. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Honeywell own?

Honeywell holds 4 OUI prefixes in the IEEE registry, of which 00:40:84 is one. A device made by Honeywell could carry a MAC address from any of them.

Honeywell

MAC address prefix 00:40:84 is registered to Honeywell in the IEEE OUI registry. Any device whose MAC address begins with 00:40:84 has a network interface built by Honeywell. 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 00:40:84:00:00:00 to 00:40:84:FF:FF:FF.

OUI prefix: 00:40:84
Hyphen form: 00-40-84
MAC range: 00:40:84:00:00:00 – 00:40:84:FF:FF:FF
Addresses in block: 16,777,216
Organization: Honeywell
Address: 512 Virginia Dr Ste A Fort Washington PA US 19034
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.

Other prefixes from Honeywell

Honeywell holds 4 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (4)

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 "HONEYWELL ACS"
archived source →
2018-12-21Renamed from "HONEYWELL ACS" to "Honeywell International HPS"
archived source →
2022-07-11Renamed from "Honeywell International HPS" to "Honeywell"
archived source →
2026-07-17Assigned to "Honeywell"

Nearby in the registry

The prefixes assigned immediately before and after 00:40:84:

FAQ

Which company owns MAC address prefix 00:40:84?: MAC address prefix 00:40:84 is registered to Honeywell in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:40:84 has a network interface built by Honeywell.
What is the OUI 00:40:84?: 00:40:84 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honeywell. It covers every address from 00:40:84:00:00:00 to 00:40:84:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-40-84.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:40:84:00:00:00 that is 00:40:84 — 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 Honeywell located?: Honeywell is listed at 512 Virginia Dr Ste A Fort Washington PA US 19034 in the IEEE OUI registry entry for 00:40:84. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Honeywell own?: Honeywell holds 4 OUI prefixes in the IEEE registry, of which 00:40:84 is one. A device made by Honeywell could carry a MAC address from any of them.