UK digital video ad spend hits £5.1 billion as TV+ grows

The double-digit growth in UK digital video ad spend confirms that streaming has transitioned from an experimental channel to a structural pillar of media buying. While the TV+ segment is scaling rapidly due to new SVOD ad tiers, the persistent 42% transparency gap suggests that technical friction in the programmatic supply chain is still capping potential investment. This shift forces a dual-track strategy where buyers use broadcaster VOD for reach and FAST/SVOD for incremental targeting. Watch for the continued rollout of ISBA Origin to see if deduplicated measurement can reclaim the 10% of spend currently lost to frequency overlap.

IAB UK has been building institutional infrastructure to address the supply-chain transparency gap that its own H1 2026 data highlights. The organization's Gold Standard certification was expanded in January 2025 to encompass CTV and retail media specifications for the first time, requiring CTV companies to implement IAB Tech Lab frameworks that standardize video delivery mechanisms and track ad creatives across platforms. The updated criteria also mandate support for IAB Tech Lab's VAST CTV Addendum 2024, which aims to enhance measurement consistency in connected environments. This directly targets the 42% barrier identified in the H1 2026 report by establishing baseline expectations for how inventory is represented to buyers.

At the European level, IAB Europe published a CTV Measurement Framework and Transparency Principles document developed in collaboration with buy-side and sell-side stakeholders including Amazon Ads, Freewheel, IAB UK, ProSiebenSat1, and Samsung Ads. The framework introduces unified metrics and definitions for CTV campaigns alongside Transparency Principles that set baseline expectations for disclosure and reporting. It found that only 30% of advertisers and publishers have full visibility into ad placements, and less than half use quality verification, data points that align closely with the UK-specific findings. IAB UK's broader transparency work includes the Cross Industry Programmatic Taskforce, a joint initiative with ISBA, the IPA, and the AOP that produced tools enabling advertisers and publishers to exercise financial audit rights over their programmatic supply chains.

The competitive landscape for UK CTV ad buying continues to intensify as more platforms enter the market and measurement solutions mature. ISBA's Origin platform, the cross-platform measurement initiative referenced by advertisers as a potential solution to frequency overlap, represents the industry's attempt to provide deduplicated audience measurement across broadcaster VOD and subscription streaming ad layers. BARB's parallel expansion of its reporting to include streaming ad-supported tiers provides a complementary dataset, though the two systems have not yet been formally reconciled. The IAB UK Gold Standard's CTV-specific requirements, combined with IAB Europe's new framework, suggest that standardization efforts are accelerating on both national and pan-European tracks, potentially reducing the complexity that currently caps CTV investment growth.