Organising for IMC: agency models, in-housing, roles and AI in 2026

Integrated communication is decided less by strategy documents than by who sits where, who owns the plan and which agencies are paid to work together. There is no single right structure, but there are recognisable models and a few processes that make any of them work.

• Agency models range from one lead agency to a holding-company team, a roster of specialists, an in-house agency, or a hybrid of these.
• In-housing is now the norm among large US advertisers: 82% of ANA members had an in-house agency in 2023, up from 42% in 2008¹.
• Roles that hold integration together: the marketing leader (CMO), the communications lead, marketing operations, and whoever owns the agency relationships.
• Processes matter more than structure: one shared brief, one shared calendar, one shared measurement plan.
• AI is used by almost all large brands in some form, but few have integrated it fully, and governance is the main work⁷⁹.

The holding-company team is the model with the longest public track record. From the 2000s, holding companies built stand-alone units for single clients, such as Team One for Toyota, GTB for Ford, Enfatico for Dell and We Are Unlimited for McDonald's; the promise was seamless work from the best people across the group, but an ANA analysis notes that the holding-company model did not readily lend itself to a blended workforce². When Ford ended its creative arrangement with WPP in 2018, it appointed Omnicom's BBDO as lead creative agency with Wieden+Kennedy as an innovation partner¹⁸. Commentators in Campaign described such teams as marriages of convenience between people with little in common but their holding company, and argued they work only where the people share a culture and creative values³.

The model has not disappeared; it has changed shape. Publicis set up One Touch, a unit that serves Nivea alone through eight creative hubs⁴, and Campaign has reported Unilever moving away from relationships with individual agencies towards wider arrangements with their parent groups⁵.

Choosing a model

• Small business or start-up: one generalist agency or a few freelancers, coordinated by the founder or marketing lead, with a written brief and calendar from day one.
• Mid-sized company: a lead agency for strategy and the core idea, a media partner, and specialists added per campaign; the client keeps the plan on a page.
• Large advertiser: usually a hybrid of an in-house agency and external partners, or a holding-company team; the integration owner sits on the client side, not inside one agency.
• Whatever the size: pay agencies to collaborate (shared meetings, shared reviews, shared credit), or they will optimise for their own scope.

The ANA has surveyed its members on in-house agencies every five years since 2008. In 2023, 82% had one, up from 78% in 2018, 58% in 2013 and 42% in 2008; the survey, fielded in February and March 2023 with 162 respondents, defines an in-house agency as a department, group or person doing work an external agency would typically do¹. The ANA expects penetration to peak at 85 to 90 percent, and 54% of in-house agencies already handle some media planning or buying¹.

In-housing does not end the need for agencies; it changes their job. The usual pattern is a hybrid in which the in-house team handles volume, speed and brand knowledge, while external partners bring strategy, big ideas, specialist skills and media scale. The World Federation of Advertisers (WFA) has been tracking how AI changes this balance (see below)⁶⁷.

For integration, in-housing helps in one specific way: the people who make the work sit next to the people who own the brand platform and the customer data. It hurts when the in-house team becomes one more silo with its own calendar.

Leadership is less stable than plans. Spencer Stuart's 2025 study found that the average tenure of Fortune 500 chief marketing officers in 2024 was 4.3 years, below the 4.9-year average for the whole executive suite, and that 66% of Fortune 500 companies (329) had a C-suite marketing leader, down from 357 the year before¹¹. Integration that depends on one leader's personality will not survive the next appointment; integration built into processes will.

Three shared processes do most of the work:

1. One shared brief. Every agency and internal team works from the same campaign brief. The BetterBriefs study found that 80% of marketers think they write good briefs while only 10% of agencies agree¹², so test the brief with the agencies before work starts (see planning frameworks).
2. One shared calendar. All activity, paid, owned, earned and shared, on one timeline, so that a press announcement, a campaign burst, an email and an event support one another rather than collide.
3. One shared measurement plan. The same objectives and KPIs for every discipline, and one review where results are compared. The IPA warns that measurement methods used separately fragment knowledge into silos¹³; see measuring effectiveness.

Judging the work together helps too: the IPA, ISBA, the MCCA and the PRCA publish a joint guide with shared criteria for judging creative ideas¹⁶.

What can be said with evidence, rather than hype:

• Adoption is near-universal among large advertisers. WFA research published in 2026 found that 96% of major brands now use AI in marketing¹⁰; Marketing Week reports the figure from a survey of 54 marketers across 46 brands, up from 45% in 2023, with the share of teams at an advanced stage of adoption rising from 16% in 2025 to 27% in 2026⁹.
• Full integration is rare. In WFA research on in-house agencies, based on a survey and in-depth interviews with 30 global in-house agency leaders, only 12% had reached full AI integration⁷; an earlier WFA update found 17% of in-house agency leaders had integrated AI into their workflows and 61% were still experimenting⁶.
• Governance is the main work. Leading in-house teams have set up dedicated AI governance teams that approve tools and use cases against ethical, regulatory and legal criteria⁷. In 2024, 80% of brands told the WFA they had concerns about how their agencies use generative AI⁸, and in 2026 brands called for a clearer consensus on labelling AI-generated content¹⁵. AMEC's Barcelona Principles 4.0 put the same emphasis on ethics and governance in measurement, including the use of AI¹⁴.

In practice, by area:

• Planning: AI helps summarise research, draft situation analyses and explore options. The brief, the choice of objectives and the trade-offs remain human decisions with a named owner.
• Content production: the biggest gains in volume and adaptation across formats and languages, and the biggest risks (brand consistency, rights, disclosure). Route AI-made assets through the same brand and legal review as any other (see consistency and adaptation).
• Measurement: machine learning is already inside open-source mix models; Meta describes Robyn as an AI/ML-powered MMM package intended, among other things, to reduce human bias in modelling¹⁷. The model still needs good data, experiments to calibrate it, and people who understand its limits.

1. Write down your current model: which agencies, which in-house teams, who briefs whom.
2. Name one owner of the integrated plan, with authority over the brief, the calendar and the measurement plan.
3. Give each agency a scope that states what it owns and what it must hand to others.
4. Run one shared brief, one shared calendar and one shared measurement review for every campaign.
5. Hold a joint planning session with all agencies at the start of each campaign, not separate briefings.
6. Set AI rules: approved tools, human review of outputs, disclosure from agencies, and how AI-made content is labelled.
7. Review the model once a year against results, and change the structure only when the processes are already working.

• The ANA's 2023 in-house agency report¹ and its analysis of delivery models².
• WFA research on in-house agencies and AI⁶⁷ and on AI use by brands¹⁰.
• Spencer Stuart's CMO tenure study¹¹.
• On IMC Institute: what is IMC, planning frameworks, consistency and adaptation, and the internal communications discipline.