IAB Forecasts AI-Driven UK Ad Spend £18bn

IAB UK forecasts that AI-driven advertising spend in the UK will reach approximately GBP 18bn by 2030, about one-third (32%) of total digital ad spend, per its report "The State of AI in Advertising: Charting the Shift from Automation to Autonomy." The report identifies four areas driving the shift: content creation, zero-click search, agentic trading, and agentic commerce (IAB UK).

The study finds that 58% of IAB UK members are experimenting with or piloting agentic AI and a further 16% are scaling agentic systems or operating "agent-first" workflows, while only 4% consider themselves fully agent-first (IAB UK). Creative production is among the most mature use cases, with 63% of members expecting an accelerating or transformative impact on creative over the next 12 months (IAB UK).

Trust remains the main brake on full adoption: 47% of advertisers say they do not trust AI agents because of limited transparency in decision-making, rising to 67% among IAB UK members (IAB UK; Marketing Week). Respondents also flagged governance, data security, and accountability as constraints. Generic industry analysis of comparable transitions suggests trust concerns tend to slow enterprise-scale deployment and increase demand for audit trails, explainability tooling, and contractual safeguards.

The report warns that AI-generated answers are reducing click-through traffic, with 74% of advertisers saying AI summaries cut traffic to brand sites and almost two-thirds already changing site structure, metadata, and content for generative engine optimization (IAB UK; Marketing Week). That points to a shift in value from share of search to visibility inside AI assistants, which the report suggests may require rethinking impression- and click-based measurement, though it does not prescribe specific standards.

Practical signals include agentic-buying adoption in search, social, and programmatic versus pilot activity; publisher and advertiser responses to AI summaries; platform feature rollouts that embed agentic optimization (for example Google AI Max and PMax, Meta Advantage+); and UK regulatory scrutiny that could shape how platforms expose agentic features (IAB UK; Marketing Week; DecisionMarketing).

The forecast implies a material reallocation of UK media planning and buying over four years. The report is produced by a trade association and is forecast-based, so figures are directional rather than guaranteed, but the documented adoption and trust data make it a useful planning input for teams owning media strategy, creative, and measurement (IAB UK).