If you’ve shopped for a Windows or Office license recently, you’ve probably noticed something strange: keys that should cost €200 are selling for €40, and the sellers all claim they’re 100% genuine. The instinct to be skeptical is healthy. Here’s what’s actually going on.
Why prices vary so dramatically
Microsoft sells software through dozens of channels at very different prices. Volume licensing for businesses, education licenses for schools, OEM keys bundled with hardware, and retail boxes at electronics stores can all carry the same product but at price points ranging from €10 to €300. Authorized resellers acquire surplus inventory from these channels — overstock from corporate liquidations, unused volume keys, region-pricing differences — and sell it at a fraction of retail.
This is fully legal in the EU under the principle of first-sale exhaustion, confirmed by the Court of Justice of the European Union in the UsedSoft v. Oracle case. Once Microsoft has sold a license to anyone, that license can be resold within the EU.
How to spot a real reseller
Look for four signals. First, the seller provides a real invoice with a registered company name and VAT number — keys sold without a receipt have no resale traceability. Second, the activation method is described clearly: “online activation” for retail keys, “phone activation” for some volume keys. Third, there’s a refund or replacement policy in writing. Fourth, customer reviews exist on independent platforms (Trustpilot, Reseller Ratings, etc.) and span more than a few months.
Red flags to walk away from
Sellers who claim “lifetime Office 365” don’t understand their own product — Microsoft 365 is by definition a subscription, so a lifetime version doesn’t exist. Anyone selling it is either confused or selling a key that will be revoked. Listings priced below €15 for a Pro version are almost always counterfeit or stolen. And any seller who refuses to provide an invoice “for tax reasons” is hiding something.
What happens if a key gets revoked
Microsoft occasionally revokes keys it identifies as obtained fraudulently. Your software starts showing “not genuine” messages but keeps working. With a real reseller, this is solved by a free replacement key under their guarantee. With a marketplace seller who has since vanished, you’re out of luck. This is the single biggest reason to buy from a reseller with a track record rather than the cheapest listing on a giant marketplace.