Legal guide
Are cheap Windows keys legal? EU law and the UsedSoft case
The CJEU judgment C-128/11 UsedSoft v Oracle
On 3 July 2012 the Court of Justice of the European Union (Grand Chamber) ruled in case C-128/11, UsedSoft GmbH v Oracle International Corp. According to the Court's press release, the author of software cannot oppose the resale of "used" licences allowing the use of programs downloaded from the internet.
The right of distribution of a copy is exhausted when the rightholder makes a copy available, tangible or intangible, and concludes, for a fee, a licence agreement without a time limit. This includes downloads. Even if the licence agreement prohibits further transfer, the rightholder can no longer oppose the resale.
The judgment rests on Directive 2009/24/EC on the legal protection of computer programs. The full judgment is on EUR-Lex and the press release on the Court's website (links in the sources).
Conditions for resale according to the Court
The press release states the following conditions and scope:
- The original acquirer must make the copy downloaded onto their own computer unusable at the time of resale.
- If the licence covers more users than the acquirer needs, they may not divide it and resell only part of it.
- Exhaustion covers the copy as corrected and updated under a maintenance agreement.
What the judgment does not decide
| Situation | What follows from the judgment |
|---|---|
| Perpetual licence bought for a fee | UsedSoft may apply if its conditions are met (seller's copy made unusable, licence not split) |
| Subscription or time-limited licence | The ruling concerns unlimited-term licences; it does not cover subscriptions or time-limited licences |
| OEM licence tied to hardware | We found no official source settling this clearly, so we claim nothing beyond the licence terms |
| A key whose origin cannot be shown | The judgment does not legitimise keys of unknown origin |
Microsoft's position
Microsoft says your safest option is always to buy Windows from Microsoft. Its licence terms also state that successful activation does not confirm that the software is genuine or properly licensed, and point to aka.ms/genuine for checking genuineness.
It is worth knowing both sides: EU law allows, under conditions, trade in used perpetual licences, while the vendor encourages buying directly from it. For transfers in Germany and some other countries the Microsoft terms refer to applicable law, which we describe in the guide on OEM, Retail and Volume licences.
Checklist: how to assess a seller
Before you buy a key from any seller, check:
- Whether the seller gives company details: name, address, registration number.
- Whether they issue an invoice or other purchase document in your name.
- Whether they clearly state the licence type (OEM, Retail, Volume) and the product edition.
- Whether they provide clear information on returns and withdrawal.
- Whether the price is realistic compared with the market; a very low price needs an explanation of where the key comes from.
- Whether you can ask a question before buying and get a concrete answer.
Red flags
Be careful when:
- Activation requires phone-activation tricks or unusual tools.
- A key is "shared" by many buyers.
- An offer promises "lifetime" Microsoft 365, a subscription that is time-limited by nature.
- The seller gives no company details or purchase document.
- The listing does not explain what type of licence it is.
What this means for a company
A company should keep the purchase document and evidence of where a licence came from, in case of an audit. We collected information for organisations on the business portal.
If you are still comparing licence kinds, start with the guide to OEM vs retail licences.
Frequently asked questions
Short answers to the questions we hear most often.
Is reselling software licences legal in the EU?
According to CJEU judgment C-128/11 UsedSoft, a software author cannot oppose the resale of used perpetual licences, including downloaded ones, under the conditions set out in the ruling. This is not legal advice.
What conditions must a resale meet?
The original acquirer must make their copy unusable at the time of resale, and a multi-user licence may not be divided and partly resold.
Does the ruling cover subscriptions such as Microsoft 365?
No. It concerns unlimited-term licences, not subscriptions or time-limited licences.
Does successful activation mean a key is legal?
No. Microsoft licence terms state that successful activation does not confirm that the software is genuine or properly licensed.
What does Microsoft recommend?
Microsoft recommends buying Windows from Microsoft and points to aka.ms/genuine for checking genuineness.
Does Softflix guarantee the legality of every key?
We make no such guarantee in this guide. We do not list the licence type (OEM, Retail, Volume) per product — if it matters to you, ask us, and use the checklist above.
Legal basis and sources
We checked licensing rules and support dates against official documents. Links open the publishers’ pages.
Licences for your company?
Business account, quotes on request and invoices in your customer panel.
