Microsoft Mobile Oy — 11 prefixes (MA-L)

Microsoft Mobile Oy was the Finnish phone-manufacturing subsidiary Microsoft stood up in April 2014 after closing its roughly $7.2 billion purchase of Nokia's Devices & Services division, and IEEE's MA-L registry credits it with 11 separate OUI blocks — 38:F2:3E, 38:25:6B, E4:98:D1, 6C:27:79, B4:E1:C4, 6C:24:83, 5C:CA:1A, 60:7E:DD, 30:0D:43, 6C:8F:B5, and A4:51:6F — all registered to the Keilaniemi campus in Espoo, Finland (the former Nokia House, since renamed "Microsoft Talo"). That block count, combined with a documented and named product line — Lumia-branded Windows Phone and Windows 10 Mobile smartphones, plus holdover Nokia Asha feature phones — is enough distinguishing substance to treat this as a legitimate consolidated vendor rather than a bare single-OUI shell. The entity's life as a phone maker was short: Microsoft exited the phone-hardware business in May 2016, selling the feature-phone line and trademark to newly formed HMD Global, and no further OUI activity under the "Microsoft Mobile Oy" name appears in the cached registry after that point. A recurring data-quality trap worth flagging explicitly for this cluster of entries: IEEE's the IEEE MA-L registry, the IEEE MA-S registry, and the IEEE MA-M registry each carry unrelated "Microsoft"-named registrants — plain "Microsoft" / "Microsoft Corp." (Redmond, WA), "Microsoft XCG", and "Microsoft Research" — that must never be merged with this Espoo-registered mobile subsidiary's address, block list, or company history.

IEEE assignment

11 MA-L prefixes → Microsoft Mobile Oy, registered Keilalahdentie 4, Espoo, FI 02150 [Confirmed] — the IEEE MA-L registry (local IEEE-derived cache)

Registry / block size

MA-L (24-bit OUI); 11 blocks confirmed under this exact org name, 0 matches in MA-M (the IEEE MA-M registry) and 0 matches in MA-S (the IEEE MA-S registry) [Confirmed] — the IEEE MA-L registry, the IEEE MA-M registry, the IEEE MA-S registry

HQ / registered address

Keilalahdentie 4, Espoo, FI 02150, Finland — ten rows read "Keilalahdentie 4"; one row (30:0D:43) reads "Keilalahdentie 2-4" — same Keilaniemi campus, ex-Nokia House / "Microsoft Talo" [Confirmed] — the IEEE MA-L registry; https://en.wikipedia.org/wiki/Microsoft_Mobile

Company status

Defunct as a phone-hardware Microsoft subsidiary — formed April 2014 on completion of Microsoft's ~$7.2B Nokia Devices & Services acquisition; exited the phone business May 2016 when the feature-phone line/trademark was sold to HMD Global [Confirmed] — https://en.wikipedia.org/wiki/Microsoft_Mobile, https://www.computerworld.com/article/1505598/microsoft-completes-7-2b-acquisition-of-nokia.html, https://en.wikipedia.org/wiki/HMD_Global

Device types

Lumia-branded Windows Phone / Windows 10 Mobile smartphones; legacy Nokia Asha feature phones [Likely] — https://en.wikipedia.org/wiki/Microsoft_Lumia (per-prefix device model not independently confirmable from the registry alone)

Notable products

Microsoft Lumia smartphone line (continuation of the Nokia Lumia brand) [Confirmed] — https://en.wikipedia.org/wiki/Microsoft_Lumia

Verified sample prefixes (all MA-L, Microsoft Mobile Oy)

38:F2:3E, 38:25:6B, E4:98:D1, 6C:27:79, B4:E1:C4, 6C:24:83, 5C:CA:1A, 60:7E:DD, 30:0D:43, 6C:8F:B5, A4:51:6F — 11 of 11 known blocks [Confirmed] — the IEEE MA-L registry

Date registered

Unknown / not recorded — IEEE's public the IEEE MA-L registry has no assignment/registration-date column. A third-party tool (maclookup.app) shows a "Date Created/Updated" of 2015-11-17 for 38:F2:3E, but per project rule that is a database artifact, not an IEEE fact, and is not attributed here as a registration date

[Confirmed] — https://maclookup.app/macaddress/38F23E; the IEEE MA-L registry (no date column present)

Distinction from other Microsoft registrants

"Microsoft Mobile Oy" is a separate IEEE registrant from plain "Microsoft"/"Microsoft Corp." (Redmond, WA), "Microsoft XCG", and "Microsoft Research" — all appear as distinct rows in the same registry files and must not share address/company fields with this entry

[Confirmed] — the IEEE MA-L registry, the IEEE MA-S registry

Related vendors

Nokia Corporation (predecessor phone business, separate registrant), Microsoft Corporation (former parent; separate registrant, see vendor-microsoft), HMD Global (2016 successor licensee of the feature-phone line) [Confirmed] — https://en.wikipedia.org/wiki/HMD_Global

Analyst note

11 confirmed MA-L blocks plus a documented, named product line (Lumia Windows Phone smartphones, Nokia Asha feature phones) place this well above the single-OUI-shell threshold — treat as a legitimate consolidated vendor entry despite the underlying company being defunct as a phone maker since 2016.