Is this a genuine Microsoft Product?

Office Professional 2021 is a volume licence version of Office used by large organizations, that is not a correct home consumer Office licence.

Most likely you would not be able to activate that licence, and even if you are able to activate the licence, it would automatically deactivate later and you would not be able to reactivate that Office licence because it is not a correct home user licence, my advice is to not purchase that licence.

Hello @RT

Be cautious with that listing. A very low price doesn't prove the product is counterfeit, and an Amazon listing alone isn't enough to verify the licensing source.

Also, make sure you distinguish Office Professional 2021 from Office Professional Plus 2021. They are different licensing products; Professional Plus is commonly associated with organizational/volume licensing rather than ordinary consumer retail licensing.

Microsoft specifically warns that product keys sold separately through third parties can be stolen, abused, or otherwise used without authorization. Such keys can sometimes activate successfully at first and later be blocked, so successful activation alone isn't proof the license is genuine.

If you want a one-time-purchase (“lifetime” for that version, not lifetime upgrades) Office license, buy from Microsoft or a reputable authorized retailer, and verify exactly which Office edition and license type the seller is providing.

Reference: Microsoft Support - Using Office product keys and safer purchasing guidance

So I wouldn't call that particular Amazon offer genuine or counterfeit without verifying the seller and license, but the combination of an unusually low price and Professional Plus/standalone-key licensing should definitely be treated as a warning sign.

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Here's a reply for that thread:

Be very cautious here — a few things about that listing are classic red flags for a non-genuine or grey-market key rather than genuine retail software:

Price gap: A steep discount off Microsoft Store pricing for a "lifetime" Office license is the single biggest tell. Microsoft doesn't sell perpetual Office licenses at fire-sale prices through third-party resellers — legitimate perpetual licenses (Office Home & Student, Home & Business, Professional) are priced consistently close to what Microsoft charges directly, give or take normal retail discounting.

"Lifetime access" claims: Genuine perpetual Office licenses are tied to one device forever, not "lifetime access" in the way it's often marketed on these listings — that phrasing is common in listings selling volume-license keys, MSDN/TechNet keys, or keys obtained through fraud (stolen corporate/education tenant keys, chargeback schemes) that work temporarily until Microsoft detects and revokes them.

Physical media/packaging mismatch: If it's a physical product (the listing title says "Full Office 2010" but you mention wanting the 2021 Professional version — worth double-checking the actual listing matches what's pictured, since mismatched titles/descriptions are themselves a red flag for these listings), check whether it ships as an actual retail box with a genuine Certificate of Authenticity, or whether it's just a key sent electronically after purchase — the latter is much higher-risk.

Seller reviews specifically about activation: On these kinds of listings, check reviews for mentions of "key stopped working," "had to contact support," or "deactivated after a few months" — this is extremely common with grey-market keys since Microsoft actively revokes keys that were obtained fraudulently or violate licensing terms, and you'd have no recourse since you're not the original licensee.

The safest way to get a permanent, legitimate Office license is directly through the Microsoft Store or Microsoft.com, or through a Microsoft Authorized Reseller (look for the "Authorized Reseller" badge Microsoft maintains a list of on their site). If budget is the concern, Microsoft 365 Personal/Family subscriptions often work out cheaper long-term than people expect, and occasionally Office Home & Student goes on genuine sale directly through Microsoft or well-known retailers like Best Buy/Costco — worth waiting for one of those rather than risking a key that gets revoked with no way to get your money back.