Before you forecast the programmatic advertising market outlook

What to take away

Key findings

Start with demand signals, not headlines

Build the outlook from identifiable evidence: record the source, reporting period, geography and measure before using a figure. Keep observed adspend separate from forecasts and from client-specific platform data.

Separate England demand from UK totals

Most published adspend research covers the UK as a whole. If your agency buys only in England, a UK growth rate will not fit an England budget. Read the sector splits and judge which categories are expanding.

The latest official UK measure we found is Ofcom's Media Nations 2026 report, published on 29 July 2026. It says the UK commercial TV and online video market exceeded £18bn in 2025, driven by the online segments, while commercial broadcaster revenues declined. Treat it as a UK proxy: it is not an England figure and it does not measure programmatic spend.

The IAB UK insight archive publishes adspend and sector research. Use the IAB UK/PwC Digital Adspend report alongside forecasts from WARC, GroupM’s This Year Next Year, MAGNA and eMarketer as cross-checks. Check each release’s date, geography and whether it measures total digital or programmatic spend; do not treat unlike measures as interchangeable.

Write down the source, publication date and geography before using any figure.

Where a source covers the UK only, label the figure a UK proxy. A proxy works as a placeholder, but it should not carry a client budget alone. If the buying runs only in England, say so beside every figure you quote.

Read regulation as a demand signal

Privacy and data use affect addressability and inventory value. The UK GDPR and Data Protection Act 2018 are the relevant data-protection framework, with the Information Commissioner’s Office (ICO) as regulator. The ASA applies the CAP Code to advertising, while the CMA is relevant to competition and consumer-protection issues, including the Digital Markets, Competition and Consumers Act 2024. The current track to watch is the review of regulation 6 of PECR for online advertising, set out below. When reviewing it, or the Online Advertising Programme, distinguish consultation proposals from requirements in force. The linked Online Fraud Charter 2023 is a separate government-industry commitment relevant to online fraud.

At present, the ICO states, all online advertising requires user consent under PECR. Regulation 6 PECR says that, unless an exception applies, organisations must not store information, or access stored information, on a user's or subscriber's device (terminal equipment) without freely given, specific and informed consent. For how this works in buying, see how UK GDPR and PECR shape programmatic advertising consent.

That position is under review. In April 2026 the ICO said the government may make changes to the regulation 6 requirements for online advertising purposes in the future, and that it understood the government was exploring an exception, or exceptions, for some online advertising purposes using secondary regulation-making powers under regulation 6A of PECR. The ICO's May 2026 cost-benefit analysis of its advice to government describes a proposed approach under which specific low-risk online advertising activities could take place without consent where appropriate safeguards are in place. A proposal and an exploration are not requirements in force: the ICO's April 2026 online tracking strategy update says that until any change is made, the law and its guidance continue to apply and all online advertising purposes still require consent. Check the current text of both documents before you rely on this.

Consent status for UK online advertising, April to May 2026

The table shows the rules as they stand, and what is proposed or being explored. Source: Information Commissioner's Office (ico.org.uk). Check the status again before you rely on it.

The ICO also said on 29 April 2026 that 99% of the UK's top 1,000 websites now meet compliance standards for cookie banners. A changed banner or vendor list is therefore still a reason to re-check reach assumptions. For the enforcement side, read ICO reprimands and consent flows.

Treat an official consultation outcome, government response or adopted legal or code change as a trigger to revisit your outlook. If a proposal would restrict a targeting method you rely on, record that as a risk scenario; change the base case when the evidence supports it.

Keep a dated log of consultation publications, government responses and any resulting legal or code changes. Record the source and distinguish proposed requirements from those in force.

Build a scenario model you can defend

Keep market evidence separate from client planning inputs. Record the buying mix and, where relevant, client-specific data from DSPs such as Google Display & Video 360 (DV360), The Trade Desk or Amazon DSP; do not present that data as a national market benchmark. Note whether buying is agency-managed or in-house.

Write assumptions before numbers

A defensible outlook has three scenarios and a written rule for each. Start with a base case: flat CPMs and steady demand from two sectors. The upside case might price in a 10% CPM rise from tighter premium inventory. The downside case allows a 15% CPM fall if one major category pauses spend.

A rule written after the numbers is a rationalisation, not an assumption. Each assumption needs a source or a labelled example. For the longer-run shifts your rules should reflect, start with the programmatic advertising trends and outlook article on demand, formats and measurement.

Give each scenario a named owner and a review date. An assumption nobody owns goes stale first.

Work a pound example

Take an agency in England with a client spending £120,000 a year on programmatic inventory. Base case: CPMs stay flat and the media budget stays at £120,000.

Upside case: a 10% CPM rise makes the same volume cost £132,000, so the agency finds £12,000 more or reduces reach. Downside case: a 15% CPM fall costs £102,000, freeing £18,000 for testing.

These are illustrative figures for an England budget, not forecasts.

Set update triggers and review rhythm

For each trigger, record the evidence to watch, the assumption it could affect and who is responsible for checking it. This makes an event trigger actionable without treating a possible change as a forecast.

Quarterly review plus event triggers

Review every quarter, and immediately when a trigger fires. Triggers include a consultation outcome, a platform targeting rule change, or a client category cutting spend. Update the scenario rules before the numbers.

Two named examples from the consent review above: a government decision to make secondary legislation under regulation 6A of PECR, and any further ICO update on regulation 6. Give each an owner and record the date it fired. The 2027 trends and update triggers article covers further triggers.

A written review note records what changed, which scenario applies and the budget impact. That note makes the outlook auditable.

The note should say which trigger fired and on what date. Assign a named person to each trigger. A trigger nobody watches is a note nobody acts on.

Test the outlook against risk scenarios

Stress-test demand, pricing and compliance separately. For each risk, record the event, evidence to watch, scenario affected, owner and budget implication. Label speculative events as risks rather than presenting them as expected market outcomes.

Common questions

Use the answers below to apply the same source, geography and scenario rules consistently.

How often should an agency update its programmatic advertising market outlook?

Quarterly as a minimum, and immediately when a trigger fires, such as a consultation outcome or a platform policy change.

Can I use UK-wide adspend figures for an England-only plan?

Only with care. UK totals include Scotland, Wales and Northern Ireland, so use sector splits and state the geography in your assumptions.

What should a scenario rule contain?

One assumption, one source or labelled example, and one budget consequence. For example, if CPMs rise 10%, the £120,000 media budget becomes £132,000 at the same volume.

When should I rebuild rather than update the outlook?

Rebuild when the market structure changes, such as a new regulatory regime or a major shift in inventory supply.

Which official UK source should a UK proxy use?

Use Ofcom's Media Nations report for UK TV and online video revenue, and the ICO for the consent rules that affect addressable inventory. Label every figure as a UK proxy and state the year it covers.

Methodology

The update uses UK official publications only: the summary of Ofcom's Media Nations 2026 report, and ICO publications from April and May 2026 on storage and access technologies and on PECR regulation 6. All figures are UK-wide and none is specific to England. No figure comes from market-research, agency or press sources. The consent position was still moving when this was written, so check the linked ICO pages for the current status.

Cite this

Editorial Desk, Media Automation (2026). "Before you forecast the programmatic advertising market outlook". https://mediaautomation.co.uk/programmatic-advertising-market-outlook-in-england