How to brief an event marketing agency: a checklist for UK brands

What to take away

A brief fixes four thingsthe objective, the audience, a budget range and the decision date.
Describe the change you want after the event, not the format you have in mind.
Cover data handling and advertising claims in the brief, because both shape cost and lead time.
Agree approval timings and reporting lines before the kick-off call.

Write the objective in one sentence

Most weak pitches come from weak briefs. Start with the change you want after the event: more qualified pipeline, a launch that lands with trade press, or renewal conversations with existing accounts. Write that as one sentence and put it at the top of the document.

Then add the constraints that shape cost. These include the date and venue, delegate numbers, whether the event is physical, digital or both, and any suppliers you insist on using. Agencies price risk, so hiding a difficult venue or a tight date costs you more later.

The seven sections of a working brief

A brief that covers these headings in order will survive the first agency call without a rewrite.

Objective and success measures
Audience and data requirements
Event concept and format
Scope and deliverables
Date, venue and logistics
Budget and commercial terms
Approvals, reporting and timeline

Seven sections of a working brief

Objectiveone sentence on the change
Audiencewho attends and job titles
Propositionthe single idea to repeat
Deliverablesregistration, content, stand, follow-up
Timingsmilestones counted back from event day
Budgetrange in pounds, VAT stated
Success measuresthree numbers for the board

Give a budget range, not a single number

A single figure invites agencies to cut scope until it fits, which is how follow-up programmes get dropped. Give a range and say what sits inside it. State whether the figure excludes VAT, because agency fees are usually quoted net. The UK standard VAT rate is 20%, but check with HMRC whether it applies to each line before comparing two quotes.

For a 120-delegate conference in England, ask agencies to price relevant budget lines separately. Use the headings below as a starting point and replace them with your own quotes:

Venue hire and related logistics
Production and audio-visual equipment
Catering
Agency fees
Travel and accommodation
Registration and data handling
Contingency

Illustrative budget for 120 delegates

Agency fees12,000 to 18,000
Venue and catering9,000 to 14,000
Production and AV7,000 to 15,000
Content and filming4,000 to 7,000
Paid media3,000 to 9,000
Contingency at 10 per cent3,500 to 6,300
Total excluding VAT38,500 to 69,300

If your range looks that wide, ask the agency to price two options rather than one. How the agency charges also matters: retainer versus project fees shifts who carries the risk of a quiet quarter.

Handle audience data and claims in the brief

Any brief that asks an agency to build a registration list or run a prize draw touches data protection law. Say which organisation is the controller, where the data will be held, and how long you will keep it. The ICO guidance on UK GDPR explains how consent, lawful bases and retention apply to marketing lists.

Promotional claims need the same care. If the campaign promises a prize, a discount or a price comparison, the rules on substantiation apply to the event creative as much as to a press ad. The CAP advertising codes bring promotions and comparative claims together in one place.

Agree the approval and reporting rhythm

Put the working rhythm in the brief as a short checklist:

Name one decision maker and one deputy, so approvals never stall on holiday cover.
Fix a weekly 20-minute call and a shared milestone tracker with columns for milestone, owner, due date, status and approval required.
Agree which numbers the agency reports and on which day, such as registrations and cost per attendee.
State payment terms, commonly 30 days from invoice, and any purchase order requirement.

Agencies plan staffing around the rhythm you describe. Vague approval lines are a common cause of missed deadlines, and they are easy to remove at the briefing stage. If you want a structure for the first meeting, our questions to ask event marketing agencies sets out what to press on.

Common questions

How long should a brief be?

Two to four pages is usually enough. Longer documents get skimmed, and shorter ones leave the agency guessing at scope. Attach brand guidelines and venue plans as separate files.

Should I share the budget before the pitch?

Yes. Agencies scope to the number they are given, so withholding it produces proposals you cannot afford and wastes a day of everyone's time.

What should the agency send back?

A written approach, a milestone plan, a named team and costed options for each route they propose. Ask for a page on measurement as standard.