Which company owns MAC address prefix A4:E9:A3?

MAC address prefix A4:E9:A3 is registered to Honest Technology Co., Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:E9:A3 has a network interface built by Honest Technology Co., Ltd.

What is the OUI A4:E9:A3?

A4:E9:A3 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honest Technology Co., Ltd. It covers every address from A4:E9:A3:00:00:00 to A4:E9:A3:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-E9-A3.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in A4:E9:A3:00:00:00 that is A4:E9:A3 — 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 Honest Technology Co., Ltd located?

Honest Technology Co., Ltd is listed at 5F, KyungDong Bldg. 906-5, Daejeon KR 305-330 in the IEEE OUI registry entry for A4:E9:A3. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Honest Technology Co., Ltd

MAC address prefix A4:E9:A3 is registered to Honest Technology Co., Ltd in the IEEE OUI registry. Any device whose MAC address begins with A4:E9:A3 has a network interface built by Honest Technology 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 A4:E9:A3:00:00:00 to A4:E9:A3:FF:FF:FF.

OUI prefix: A4:E9:A3
Hyphen form: A4-E9-A3
MAC range: A4:E9:A3:00:00:00 – A4:E9:A3:FF:FF:FF
Addresses in block: 16,777,216
Organization: Honest Technology Co., Ltd
Address: 5F, KyungDong Bldg. 906-5, Daejeon KR 305-330
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 "Honest Technology Co., Ltd"
archived source →
2026-07-17Assigned to "Honest Technology Co., Ltd"

Nearby in the registry

The prefixes assigned immediately before and after A4:E9:A3:

FAQ

Which company owns MAC address prefix A4:E9:A3?: MAC address prefix A4:E9:A3 is registered to Honest Technology Co., Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:E9:A3 has a network interface built by Honest Technology Co., Ltd.
What is the OUI A4:E9:A3?: A4:E9:A3 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honest Technology Co., Ltd. It covers every address from A4:E9:A3:00:00:00 to A4:E9:A3:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-E9-A3.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in A4:E9:A3:00:00:00 that is A4:E9:A3 — 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 Honest Technology Co., Ltd located?: Honest Technology Co., Ltd is listed at 5F, KyungDong Bldg. 906-5, Daejeon KR 305-330 in the IEEE OUI registry entry for A4:E9:A3. This is the address the organization registered with the IEEE, which may differ from its current operating address.