Next steps for Halo and cross-media measurement in 2026

Advertisers need reliable reach and frequency, yet the highly fragmented digital environment has made it impossible to credibly and accurately calculate this data.

Modern cross-media measurement requires approaches that incorporate privacy-safe event-level signals from media owners, built on genuine collaboration across platforms, publishers, broadcasters and other stakeholders.

This is why the voluntary Halo framework was created. Built through industry collaboration, it is based upon a set of common, open-source technology components that enable measurement organizations to build locally adapted, robust, privacy-preserving systems for measuring deduplicated reach and frequency.

Video: Marketing leaders share why Halo is important to global advertisers

Known for its approach of assigning campaign impressions to virtual proxies of a population (‘Virtual Persons Framework’), Halo answers the WFA’s North Star call. From a core of two pilot markets, the aspiration is that others will follow, propagating an advertiser-centric framework and delivering complete cross-media metrics worldwide.

Progress made in 2025

In 2025, Halo made huge progress, by adapting and refining the initial open-source releases:

• APIs are evolving into stable, advertiser-facing interfaces capable of supporting bespoke reporting needs across markets;
• The algorithms at the heart of reach and frequency estimation have been improved, enabling richer forms of deduplication while unlocking more granular business value without compromising privacy; and
• The new ‘Data Provider Module’ has progressed, transforming the process of integrating publishers into locally deployed systems and, potentially, opening the door to new commercial models that improve scalability for users.

From a non-technical perspective there’s been progress too. Halo’s governance framework has been evolving, moving from foundational principles towards a structure that can accommodate the needs of users using Halo components.

Today a broad, multidisciplinary community spanning advertisers, platforms, broadcasters, measurement companies, agencies, National Advertiser Associations, auditors, academics, Joint Industry Committees (JICs) and engineering teams all participate in the initiative, ensuring Halo remains neutral, open and shaped by the full media ecosystem.

Comprehensive anti-trust compliance training has been developed and launched, ensuring that all contributors are fully aligned with their respective roles and responsibilities.

This journey has been aided by the experience of the two organisations building a data ecosystem around the framework. Together, the core open-source framework and local operational organisation form a complete measurement product with the market’s operational machinery bringing Halo to life.

Currently in its ‘Expanded Availability’ phase, Origin in the UK represents the most mature deployment: a full end-to-end implementation operating under national governance, integrating broadcast TV, digital platform and panel data into a single privacy-preserving measurement pipeline. Covering in excess of 60% of the UK ad market by spend, Origin demonstrates that Halo’s architecture can function reliably in one of the world’s most complex and demanding advertising markets.

Also supported by the same partners (Kantar Media and Accenture), and through partnership with Origin on shared infrastructure, Aquila (US) is progressing on a comparable path. Focused on onboarding major platforms, scaling data-provider integrations and building the operational processes that support national deployment, Aquila has been able to progress to its trial phase remarkably quickly. Trials kicked off in Q4 this year with a large cohort of advertiser participants.

What to Expect in 2026

We’re focused on developing scale, stability, and expanded measurement and analytics capability for users and have got great plans for the year ahead:

More scale & stability: A major emphasis will be placed on reliability and total cost of ownership, ensuring that Halo-based systems can operate as national infrastructure with predictable performance and sustainable long-term economics. Working with its stakeholders and the industry, Halo will also continue to pursue a more formal and stable governance model.

More advanced use cases: We’ll be working with the industry on research into more advanced use cases (such as outcome studies and broader analytics capabilities) potentially extending Halo’s value beyond reach and frequency while remaining true to its core privacy and neutrality commitments.

Audit: Formal audit preparation is underway, with a defined scope and active discussions with independent auditors in advance of the first full technology audit planned.

Community growth: As Halo is proven to be an effective framework for producing cross-media reach and frequency, it’s expected that more contributors will continue to gravitate to the initiative. We’re keen on collaborating with more contributors (measurement companies, JICs, broadcasters, agencies and others) to actively participate in the development of methodology – shaping and deploying the framework as it expands beyond the UK and US.

As Origin and Aquila achieve ‘product-market-fit’ in 2026, for Halo, the further future will be on supporting other market users. For our part, the focus will be on reducing the barrier of entry, with more turnkey deployment and lighter operational requirements, which we think is attractive to the industry.

But while it’s our job at WFA to listen to global advertisers, naturally we are not so well plugged-in to the rest of the industry. So, one other project for 2026…in collaboration with the Coalition for Innovative Media Measurement (CIMM), this year we are also embarking upon a strategic review of cross-media measurement in Europe. The intention is to (re)review what the industry wants from CMM and which methodological approach is most attractive.

It's going to be a busy year!