Transparency has applied since August 2, 2026. The December 2, 2026 date is a marking transition for systems already shipping, not a delay of the whole Act.
Edited by Emilio Santos. October 1, 2026. Updated October 24, 2026.
A buyer whose employees or customers in the EU will see an AI feature, including a feature switched on inside software you already pay for.
This is an operator checklist, not a legal opinion and not a finding that your use is covered. The European Commission’s AI Act Service Desk says Article 50 transparency rules started to apply on August 2, 2026. It also says that for certain generative systems already placed on the market before that date, the Article 50(2) machine-readable marking duty has a transition that ends December 2, 2026. The Council’s timeline records the high-risk delay separately: December 2, 2027 and August 2, 2028. Do not let a vendor use the high-risk date to answer a transparency question.
| Date | What the public timeline says |
|---|---|
| August 2, 2026 | Transparency rules apply. Enforcement for those rules is underway. |
| December 2, 2026 | Marking transition ends for certain generative systems already on the market. New prohibitions on non-consensual intimate imagery and child sexual abuse material generation also apply. |
| December 2, 2027 | Stand-alone high-risk duties. Not the transparency date. |
| August 2, 2028 | High-risk duties for systems embedded in regulated products. |
Article 50 of the AI Act, Regulation (EU) 2024/1689, sets transparency duties for certain AI systems. In plain terms:
Note the split between provider duties and deployer duties. If you buy a product and use it, you may be a deployer. The vendor is usually the provider. Your contract should say who does what.
Illustrative case. A company uses a customer service chat assistant on its EU website and an image generator for social media ads. For the chat assistant, the buyer asks the vendor to show the screen where customers are told they are talking to an AI system. For the image tool, the buyer asks what machine-readable mark is applied to generated images, and whether the tool was on the market before August 2, 2026, which would put it in the transition ending December 2, 2026. If any ad image is a realistic depiction of a real person or event, the company, as deployer, plans its own disclosure.
The AI Act sets fines for breaches of the transparency obligations of up to 15 million euros or 3% of total worldwide annual turnover, whichever is higher, with lower caps for small and medium-sized companies. That is a reason to keep a record of the review, not a reason to panic. The timeline for everything else in the Act is in What the EU AI Act still applies.
It matters if the vendor, the user, or the customer is in the EU, or if the contract pushes EU duties onto you. The checklist is the question list. Counsel decides whether you are a provider or a deployer.
Regulation (EU) 2024/1689 on EUR-Lex, read with the Commission timeline that includes later amendments. Do not brief from a blog’s date if it disagrees with those two.