Annual General Meeting arrangements

System1 Group PLC (AIM: SYS1)

 (“System1”, or “the Company”, or “the Group”)

Annual General Meeting arrangements

System1 www.system1group.com, the marketing decision-making platform, announces that, while it remains in an offer period, no questions or statements will be taken from the floor at the Annual General Meeting to be held on 25 September 2026.

Shareholders are encouraged to submit questions in advance through the Investor Meet Company platform in accordance with the arrangements set out in the Notice of AGM.

The Company will arrange a separate shareholder forum to discuss questions received ahead of the AGM as soon as reasonably practicable. A further announcement will be made in due course.

The same notice is also available on the Company’s website.

For further information, please contact:

About System1 Group plc

System1 is a marketing decision-making platform business, utilised by some of the world’s largest brands, across 81 markets globally. Since 2000, System1 has helped marketers tap into consumers' emotions to predict and improve the commercial impact of ads and ideas. Drawing on the world’s largest database of emotional norms, our advertising and idea tests measure emotion to give our customers the most accurate predictions of the business impact of creativity. We 'predict' (provide research results) and work with our customers and 'improve' (provide insight and consultancy on those results) advertising effectiveness, innovation effectiveness and brand effectiveness.

We work with more than 600 clients, including 48 of the world's top 100 brands by media spend, 5 of the top 10 US and 8 of the top 10 UK advertisers.

Further information on the Company can be found at www.system1group.com.