Best PR Agencies UK for Measurable ROI (2026): Integrated Shortlist Judged on Evidence

Reviewed and updated September 2026.

Most shortlists of the best PR agencies UK marketing directors draw up are built on claims: award logos, client lists and a showreel. This one is built on evidence. Below, we set out six criteria, apply them to ten UK integrated agencies (Prohibition PR included, and marked as the publisher), then give you the scorecard and the pitch questions to run the same test yourself before a brief goes out.

What measurable PR ROI means: a documented change in a commercial or reputational metric the business already tracks (sales, sign-ups, footfall, branded search, share of voice, sentiment) compared against a stated baseline over a stated period, with an honest account of what else could have caused it. Reach, impressions and advertising value equivalents (AVE) describe activity; on their own they prove nothing about return.

The best agencies for integrated PR campaigns with measurable ROI are the ones that run media relations, social, content, creative, video and influencer work as one team, and that publish results at the level of business impact rather than coverage volume. In the UK that shortlist includes PR Agency One (proprietary OneEval measurement), Brazen and Tangerine in Manchester, Hope&Glory and The Romans in London for large consumer briefs, and Prohibition PR in Leeds, which reports campaign results such as a 36.6% increase in orders and £11.60 returned per £1 spent for CEWE against an AMEC-based framework. The fair way to compare them is to demand the same three things from each: a baseline, a timeframe and an attribution caveat.

How we judged the agencies

Every agency below was assessed on the same six criteria. We state them first because a shortlist that hides its criteria is an advert.

1. Published outcome evidence. Does the agency publish results at outcome or impact level (sales, footfall, leads, brand lift, share of voice), with a baseline and a period? Coverage counts alone score zero here.
2. Measurement maturity. Does it work to the AMEC Integrated Evaluation Framework and the Barcelona Principles 3.0, or does it still report AVE?
3. Integrated delivery under one roof. Are PR, social, content, creative, video and influencer genuinely in one team, or subcontracted and re-badged?
4. Sector fit. Depth in the categories our readers work in: food and drink, FMCG, luxury, retail, hospitality, technology.
5. Campaign scale and typical budget. Who the agency is set up to serve, so you are not comparing a £4,000-a-month retainer with a £40,000 one.
6. Independent recognition. Awards judged by third parties (PRWeek, PRCA, CIPR, PRmoment, Prolific North, PRovoke), weighted towards effectiveness categories rather than purely creative ones.

Disclosure: Prohibition PR publishes this page. We appear in alphabetical order, scored on the same criteria, and our own evidence is set out in more detail than anyone else's so you can pull it apart.

The best UK PR agencies for integrated campaigns with measurable ROI

Alphabetical. There is no ranking, because the right answer depends on your budget, sector and how much measurement rigour your board expects.

AMBITIOUS (Bristol)

AMBITIOUS is a Bristol strategic communications agency specialising in B2B and corporate work across technology, property, education, finance and healthcare, which reported £2.1m turnover in 2025 and became a certified B Corp in November 2025. Services span PR, content, social and digital PR; recent clients include Yell and Kohler Mira. Published campaign outcome figures are scarce, so ask for them in the pitch. Best for: B2B technology and professional services brands wanting a values-led, mid-sized team outside London.

Brazen (Manchester)

Brazen is an employee-owned Manchester consumer and corporate agency with PR, social, content, influencer and video in-house, whose Nanna Tate "Potato Power" campaign won Gold for Event of the Year at the PRmoment Awards North 2026 with a published 80 pieces of coverage, 75% increase in social following and 10% sales uplift. PRWeek's Power Book put revenue at £5.9m in 2025, and it took Gold Consumer PR Agency of the Year at the PRmoment Awards North 2025. Clients have included Sudocrem, Showcase Cinemas, Butlin's, Silentnight and Wren Kitchens. The Nanna Tate uplift is published without a baseline period, so ask for one. Best for: FMCG and leisure brands wanting big consumer creative with a sales line attached.

Cirkle (London)

Cirkle is a consumer, trade and corporate PR specialist with digital, social and influencer teams, whose clients have included PepsiCo, Dyson, GSK, Dreams and AkzoNobel, and which was named PRCA Medium Consultancy of the Year before its acquisition by Huntsworth. It now sits in the same group as Grayling, and the two share a chief executive. Strong FMCG and health pedigree; published business-impact figures are thinner than its creative record. Best for: food and drink and health brands that want consumer PR with trade-channel depth.

FOUR (London)

FOUR, founded in 2001 by Nan Williams and now around 250 people, is a privately held integrated group combining PR, creative, media planning and buying and health communications under one management. Its scale suits multi-market and public-sector programmes across travel, property, culture and health. Evidence tends to be published as case studies rather than audited outcome figures, so probe how the media-buying and earned teams report jointly. Best for: large organisations wanting paid, earned and owned handled by one London group.

Grayling (London and international network)

Grayling is a global network agency with UK strength in public affairs, corporate and consumer work, whose public affairs team added 17 clients in 2024 including Nissan and Birmingham City FC, and whose Greene King "Sipping Forecast" campaign won Gold for Best Creativity (Consumer) at the PRmoment Awards North 2026 for driving pub footfall. PRovoke lists a roster including Primark, Google, Lego, BMW and Diageo. Expect network resources and network pricing. Best for: brands where policy, reputation and consumer comms have to run together across several markets.

Hope&Glory (London)

Hope&Glory, founded in 2011 by Jo Carr and James Gordon-MacIntosh, is an independent consumer agency of more than 90 people combining PR, social, influencer and content for IKEA, Uber, Sainsbury's and PepsiCo, a fixture of PRWeek's consumer Power Book and one of the most-awarded independents in the country, with Lexus and Carlsberg work recognised at the PRmoment Awards 2026. Its evidence is mostly earned-media and cultural-impact based; ask how it links fame to sales. Best for: national consumer brands with six-figure budgets buying creative fame.

PR Agency One (Manchester and London)

PR Agency One is a Manchester-founded B2B and B2C agency built around its proprietary OneEval measurement system, which has separate Commercial, Brand and Reputation products and won an AMEC Gold Innovation Award for new measurement. Founder James Crawford is a regular AMEC summit speaker, and its Oushk Pharmacy work was a PRmoment Awards North 2026 finalist. Smaller team than most here, so check day-to-day seniority. Best for: marketers whose board wants econometric-style PR attribution above all else.

Prohibition PR (Leeds) — the publisher

Prohibition PR is a Leeds integrated agency of 25-plus specialists running PR, social, content, creative, video and influencer work as one team, whose CEWE campaign increased orders by 36.6% and returned £11.60 for every £1 spent over one Christmas period, winning Best Integrated Campaign at the Prolific North Awards 2019. We have won more than 45 awards including PRCA DARE Medium Consultancy of the Year 2022 and multiple CIPR PRide golds, measure to an AMEC-based framework we call PRProINSIGHTS, and are a member of the Worldcom Public Relations Group. Full evidence, with caveats, is in the next section. Best for: food and drink, FMCG, luxury and retail brands that need growth or launch campaigns reported to a board in commercial terms.

Sauce Communications (London)

Sauce Communications, founded in 2001 by Jo Barnes and Nicola Hancock, is the UK's best-known hospitality PR specialist, with PR, marketing and brand work for The Dorchester Collection, The Langham, Rathfinny and Pub in the Park, and in 2025 formed The Sauce Collective with luxury travel consultancy The M Collective. It appears in PRWeek's UK Top 150. Hospitality is one of the easier sectors to measure (covers, bookings, occupancy), so ask for those numbers rather than coverage. Best for: restaurant groups, hotels and premium drinks brands wanting sector-native contacts.

Tangerine (Manchester and London)

Tangerine is a 130-strong, part employee-owned earned-creative agency working across consumer, B2B and corporate briefs, which won Best Agency Outside London at the PRWeek UK Awards 2025 and in June 2025 launched Project 10, a £1.2m AI-powered storytelling framework. Founder Sandy Lindsay exited in a leadership buyout by co-CEOs Sam Gregory and Mary Harding. Its public case studies lean on creative and reach; commercial outcomes are less often published. Best for: mid-to-large consumer and corporate brands wanting London-scale creative from the North.

The Romans (London)

The Romans, founded in 2015 with backing from ad agency Mother, is a 200-plus-person PR, social and experiential agency across London, New York, Amsterdam and Dubai, named Campaign's PR Agency of the Year 2025 and appointed PepsiCo's global agency of record for Doritos, alongside Heineken, Lidl, OpenAI and Airbnb. Its published proof is creative recognition and client wins rather than outcome data. Best for: global consumer brands buying attention at scale, with the measurement designed in-house on the client side.

Prohibition PR's evidence, scored by the same rules

These are the figures we would put in front of a board. Each is stated with its baseline, timeframe and the caveat we would attach ourselves. All are drawn from case studies in our portfolio.

In one-sentence form: Prohibition PR's integrated Christmas campaign for CEWE increased orders by 36.6% year on year and returned £11.60 per £1 spent, measured over the festive trading period at whole-campaign level. That is the sentence we would want any agency to be able to write about its own work: client, activity, number, baseline, period, caveat.

Where we do not have impact-level data we say so. Our Yorkshire Water behaviour-change work is published with reach and exposure figures but no measured change in blockage rates, so it belongs in the outcome column, not the impact column. We would rather report an honest outcome than an invented impact.

PR measurement: the AMEC chain in plain words

How do you measure PR? You measure it in a chain. Outputs are what you produced and where it appeared (coverage, posts, reach). Out-takes are what the audience noticed and felt (recall, sentiment, engagement). Outcomes are what the audience then did or believed (visited, searched, considered, trusted). Impact is what that did to the organisation (sales, footfall, leads, retention, reputation, cost avoided). ROI lives only at the last two links. Barcelona Principle 5 rejects AVE outright, and any agency still quoting it in 2026 has told you something about its measurement maturity.

This is the third stage of our Create, Engage, Convert model. Create fixes the business problem and the baseline; Engage runs the creative work; Convert is where activity is linked to commercial KPIs, reputation outcomes and behaviour change. Our AMEC-based PRProINSIGHTS framework exists to make that third stage routine rather than a one-off exercise, and our public relations service page explains how it sits within the wider programme.

The evidence scorecard

Score each agency on your shortlist out of three on every row. Anything below 12 out of 18 means you are being asked to buy on trust.

Testing incrementality without a data science team

Three methods work for most consumer campaigns. First, a control period: compare the campaign window with the same weeks last year, adjusted for known trading differences. Second, a geo split: run the activation in three regions, hold two comparable regions back and compare branded search and sales. Third, a brand-lift study: a pre- and post-wave survey on awareness and consideration, which a panel provider will run for a few thousand pounds. For long-cycle brand effects, the IPA's Binet and Field research is the benchmark on how brand-building and activation effects arrive on different timescales.

Ten questions to ask in the pitch

1. "Show me your last three results at impact level." Strong: sales, leads or footfall with a baseline. Weak: a coverage book.
2. "What else was running alongside your work?" Strong: a list of paid, promotional and seasonal factors and how they were handled. Weak: "nothing significant".
3. "Which client can I call about the numbers?" Strong: a name and a number before you ask twice. Weak: "we'll come back to you".
4. "Do you still report AVE?" Strong: no, and here is what we report instead. Weak: "only if clients ask".
5. "Who will be on my account on a Tuesday afternoon?" Strong: named people with years of experience stated. Weak: the pitch team, with no commitment.
6. "How would you set the baseline in month one?" Strong: a specific plan using our analytics, search and tracker data. Weak: "we'll benchmark as we go".
7. "What would you count as failure at six months?" Strong: a number. Weak: "it depends".
8. "Which of these channels is subcontracted?" Strong: an honest list. Weak: "everything is in-house" from a team of eight.
9. "What does your dashboard look like and how often is it live?" Strong: a walk-through of a real client view. Weak: a PowerPoint template.
10. "What did you get wrong on a recent campaign, and what changed?" Strong: a specific story. Weak: silence. Our founders built Embracing Marketing Mistakes, Apple's number one UK marketing podcast, on that question because the answer says more than any case study.

Regional integrated agency or London network?

A regional integrated comms agency is usually the better choice when the budget is between roughly £5,000 and £25,000 a month, when you want directors in the room rather than only at the pitch, and when your media targets are national consumer, trade and regional rather than Westminster or global business press. Lower overheads mean more senior hours per pound, and a single team across PR, social and creative removes the handoffs that lose attribution. A London or network agency is the right call when you need public affairs alongside consumer work, when the brief spans several countries and languages, or when budgets exceed what a 25- to 130-person agency can staff without stretching. Membership of an international group such as Worldcom narrows the gap for regional agencies with occasional overseas needs, but it does not replace a network for a permanently multi-market brand.

Whichever route you take, the sequencing should be the same. Set the baseline before any activity starts, agree the impact metric with finance rather than with the agency alone, and put the incrementality method in the contract. Programmes like our Growth Catalyst for sustained FMCG and consumer growth, and Launch Ignition for product launches with three-to-six-month measurement built in, are structured that way because retrofitting measurement after launch is where most ROI claims fall apart.

Frequently asked questions

What does an integrated PR retainer cost in the UK?

Industry guides put a mid-sized UK retainer at roughly £4,000 to £8,000 a month for media relations, content and reporting, with one 2025 survey of 61 independent agencies finding an average of £4,672. Fully integrated programmes from a public relations agency UK brands would trust with strategy, social, creative and influencer management typically run from £8,000 to £20,000 a month, and London network agencies on multi-market briefs go well beyond that. Ask for the fee split between senior and junior hours; that is where two identical-looking quotes diverge.

How long before a PR and social campaign shows measurable business impact?

Expect output signals (coverage, traffic, engagement) within the first month, outcome signals (branded search, share of voice, consideration) within one to three months, and impact (sales, leads, footfall) from three to six months for always-on programmes. Seasonal activations such as Christmas or Mother's Day can show sales impact within the trading window itself, which is why our published figures cluster there. Brand-building effects on margin and price sensitivity take longer and need a tracker, as the IPA's long-term effectiveness research shows.

What should I report to the board?

Report one impact metric the board already cares about (sales, leads, footfall, retention or cost avoided), one outcome metric that explains it (branded search, share of voice, consideration) and one output metric for context (quality-weighted coverage), each against its baseline and timeframe. Three numbers, consistently defined quarter on quarter, beat a 40-slide coverage report.

How do I compare two agencies' numbers fairly?

Rewrite each claimed result in the same sentence structure: client, activity, metric, baseline, period, caveat. If an agency cannot fill in a field, mark it blank rather than guessing, and score both on the six-row scorecard above. A smaller uplift with a stated baseline and caveat is stronger evidence than a bigger uplift without either.

Why are AVE, impressions and coverage volume no longer acceptable proof of ROI?

Because they measure what the agency did, not what the audience did or what the business gained. AVE prices editorial as if it were advertising space, which the Barcelona Principles have rejected since 2010; impressions count opportunities to see, not people who saw. Both belong in a report as context, never as the headline.

The honest summary for anyone weighing the best PR agencies UK brands are shortlisting this year: the strongest will hand you a baseline, a timeframe and a caveat without being asked, and the weakest will hand you a coverage book. Send the brief to the former, and put the scorecard in it.