How to read Barb, Rajar, Jicmail and Ukom data as a UK media buyer

What to take away

What each UK audience currency actually measures

A currency is the number the industry agrees to trade on. It is not the only measurement available, but it is the one agencies, broadcasters and publishers accept in negotiations.

That joint funding matters. A broadcaster cannot simply redefine its own audience, and an agency cannot invent a rival number, without both sides agreeing to the change. The currency is a shared contract as much as a measurement.

The four currencies also differ in what counts as exposure. Television is counted in minutes viewed. Radio is counted in quarter hours listened. Mail is counted in items received and interactions. Online is counted in people and time.

Because of that, a thousand contacts in one currency is not equivalent to a thousand in another. Media planning across media means accepting four different units and translating between them carefully.

Each currency also carries a demographic frame. Age, sex and social grade are standard. Region is available in some but not all, and the regional detail is where most planning mistakes begin.

If you are briefing a specialist agency on which currency to lead with, the channel currencies decision usually follows the medium split rather than the other way round.

How the Barb panel is built and what it covers

Barb, the Broadcasters' Audience Research Board, has measured UK television since the early 1980s and is jointly owned by the BBC, the commercial broadcasters and the IPA on behalf of agencies. The Barb panel is a continuous establishment survey with metered households, not a census.

Panel households have meters attached to every television set in the home. The meter records what is being watched and for how long. People in the household log in, usually with a handset, so viewing is attributed to individuals rather than to the set alone.

The panel is recruited to be representative of UK television households. Barb publishes its panel size and its reporting thresholds. Figures below those thresholds are marked as unavailable rather than published as if they were solid.

Reporting is daily for overnight figures and consolidated after about a week, once timeshifted viewing has been captured. The consolidated number is the one to quote. Overnight figures understate any programme that gets recorded.

Barb reports at several levels. Programme ratings, commercial impacts, reach and frequency, and time spent. It also reports by platform, which now includes viewing through apps and connected devices as well as broadcast.

Regional reporting is available across the UK, including the nations and the main English regions such as the North West, West Midlands and Yorkshire and the Humber. Regional sample sizes are smaller, so regional figures carry wider confidence intervals than national ones.

A practical point for buyers: Barb measures viewing, not advertising exposure. A spot in a break is not the same as a programme rating. Spot-level data comes through the sales house, and you should ask which Barb base it uses.

RAJAR and the radio diary and meter method

RAJAR, Radio Joint Audience Research, is the UK radio currency and is jointly owned by the BBC and commercial radio through Radiocentre. Its method combines a paper or online diary with an electronic meter, which is unusual among radio currencies worldwide.

Participants complete a diary for one week, recording listening in quarter-hour blocks. A subsample also carries a meter that detects inaudible audio watermarks, which is used to validate and correct the diary.

The RAJAR method is published each quarter and reports reach, average hours per listener and total hours. Survey periods are quarterly, with results released roughly six weeks after the period ends.

RAJAR measures listening, and it counts live listening separately from on-demand and podcast listening. That split matters. A station can be strong on live reach and weak on on-demand, or the reverse.

Digital listening now accounts for a large share of total hours, and RAJAR reports it separately by platform. If your plan relies on digital audio, ask for the digital share rather than the total.

Regional reporting covers the UK nations and the main English regions, plus London. Commercial radio is also sold on a set of approved geographic areas that do not map neatly onto government regions.

Two cautions for buyers. First, RAJAR measures station listening, not spot listening, so a campaign's exposure depends on the spot schedule. Second, diary-based recall favours habitual listening, which tends to flatter stations with loyal audiences.

JICMAIL and the mail measurement currency

JICMAIL, the Joint Industry Currency for Mail, measures what happens to mail in the home. It is funded by Royal Mail, Whistl, the IPA and ISBA, among others, and covers addressed mail, door drops and business mail.

The method is a panel of households and businesses that log the mail they receive over a period. For each item, panellists record whether it was opened, read, kept, passed on or thrown away.

That produces two families of figures. Item reach, meaning how many items were received, and interaction rates, meaning what proportion of items got a response of some kind. JICMAIL reports both, plus the commercial actions that follow.

JICMAIL's distinctive contribution is the attention and action data. It can tell you how long an item was looked at and whether it prompted a visit to a website, a store visit or a purchase. That is more than most currencies offer.

Reporting is quarterly, with the panel running continuously. Figures are available by sector, by mail type and by audience segment, and there is a business mail panel as well as a consumer one.

For a media plan, JICMAIL is usually used to justify a mail element rather than to buy it. The buy itself is priced on volume and distribution, and the currency supplies the quality and response assumptions.

Be careful with interaction rates. They are per item, not per person, and they are self-reported. A high interaction rate on a small mailing is not the same as a large reach figure.

UKOM and UK online audience measurement

UKOM, UK Online Measurement, is the industry body that governs the UK's online audience currency. It does not collect the data itself. The measurement is delivered by a contracted supplier, currently Ipsos iris, under UKOM's rules.

The method combines a metered panel of people with census-level tagging data from participating publishers. The panel gives demographic detail and cross-site behaviour. The census data corrects the panel for the very large and very small sites the panel would otherwise misjudge.

UKOM reports unique visitors, page views, time spent and demographic composition for the sites and apps in its reporting. It covers the UK population and reports by age, sex and region, with London and the larger English regions broken out.

There are limits. UKOM covers sites and apps that participate or are captured by the panel. Walled gardens, including the largest social and search platforms, are largely outside the currency, so their audiences are not directly comparable.

UKOM figures also lag. Reporting is monthly with a delay, so a plan built in September is usually working with data from a month or two earlier. Say so if the plan depends on a fast-moving audience.

For planning, UKOM is the closest thing to a common denominator for display and content sites. It is not a campaign measurement tool, and it should not be used to judge a single campaign's delivery.

If you are comparing UKOM against platform-reported reach, you are comparing two different things. Platform figures count logged-in users or cookies, not people, and they are not audited to the same standard.

Quoting currency figures in a media plan without misreading them

Most errors in UK plans come from quoting a figure without its conditions. The fix is procedural, not analytical. Work through these steps for every number that goes into a plan.

Here is a worked example. Suppose you are planning a campaign across television and radio in the North West and West Midlands, with a target of adults aged 25 to 54.

You take a Barb consolidated figure for the period, at national level, for adults 25 to 54, live plus timeshift. You then ask the sales house for the regional break, and you note that the regional sample is smaller.

You take a RAJAR quarterly figure for the same demographic, live and on-demand separated, and you check which commercial radio areas cover your two regions. Those areas will not match the government regions exactly.

You write both numbers into the plan with their conditions attached, and you do not add them together. Television minutes and radio hours are different units, and summing them produces a number nobody can defend.

Before the plan goes out, run this checklist.

If you are building the reporting side of the plan at the same time, the measurement and reporting conventions you set now will decide what you can prove later.

Where the currencies disagree and what to do

Disagreement between currencies is normal, and it is usually definitional. The same campaign can look larger on one currency and smaller on another without either being wrong.

The most common gap is between panel-based and platform-reported figures. A platform counts devices or accounts. A currency counts people. The gap is largest among younger audiences and on mobile.

A second gap is between live and on-demand. Radio and television both split these, and a plan that quotes a total without the split can overstate live exposure considerably.

A third gap is geographic. Currency regions, commercial sales areas and government regions are three different maps. The ONS publishes population estimates that let you weight a regional figure to the population it actually represents.

The ONS also publishes wider people, population and community data, including household composition and internet use, which is useful when you need to sanity-check whether a panel is likely to represent a segment.

When two figures disagree, do not average them. Averaging two definitions produces a third definition that nobody owns and no one can audit.

Instead, pick the currency that matches the decision. If you are buying television, Barb governs. If you are buying radio, RAJAR governs. If you are buying mail, JICMAIL governs. If you are buying display on measured sites, UKOM governs.

Then note the alternative figure in a footnote, with its source and its definition. That way the client sees the range and understands why you chose one number over another.

There is a governance layer too. The ASA enforces the CAP Code, and audience claims in advertising must be substantiated. The CMA takes an interest in comparative claims. The ICO governs personal data used in targeting under UK GDPR and PECR.

That means an audience figure in a client-facing plan can become a regulatory issue if it is repeated publicly without its conditions. Keep the conditions attached.

Finally, keep a record of the faults you find. Repeatedly quoting overnight figures as if they were consolidated, or mixing platform and currency numbers, are the kinds of media measurement faults that undermine a plan long before the results come in.

If you need to compare your plan against sector norms, use published currency data rather than an invented average. The approach set out in these media buying benchmarks is to anchor every comparison to a named currency and period.

Common questions