Seven matters to settle in writing before appointing a media buying agency

A useful agency contract makes the buying route inspectable. It identifies the contracting party, separates remuneration from media and technology costs, explains data roles, grants workable audit access and states what the advertiser receives at exit. Send the final drafting to a qualified solicitor; this list turns operational uncertainty into questions for that review.

What to take away

Inclusion method and limits

Entries were included where a public authoritative record, checked on the research date of 5 September 2026, supported a contract question for an advertiser operating in England. This was desk research, not contract negotiation or agency testing.

Seven matters to settle in writing

1. Contracting entity

Match the proposal, insurance, purchase order and invoice to a legal name and company number. GOV.UK explains how to search the Companies House register, while warning that filed information needs careful checking. The register does not rate financial strength or service quality. Ask counsel how guarantees or group-company services should be documented.

Sample wording: 'The agency confirms its legal name and company number on every proposal, purchase order and invoice.'

2. Remuneration and money flow

List fees, commissions, technology charges, research licences, production costs, taxes and benefits received elsewhere in the supply chain. ISBA's agency contract compliance audit guidelines (accessed 5 September 2026) discuss UK advertiser concerns including audit access, remuneration and stewardship. They are dated guidance, so the executed wording needs current professional review.

Sample wording: 'Fees, commissions and technology charges are itemised separately from media costs, and any supply-chain benefit is disclosed.'

3. Inventory basis and interests

State whether the agency acts for the advertiser, resells inventory, uses a group arrangement or recommends proprietary media. ISBA's proprietary media guidance announcement (accessed 5 September 2026) points UK advertisers towards transparency, governance and data questions. Ask what interest exists, what alternatives were considered and what disclosure the advertiser receives.

Sample wording: 'The agency discloses any proprietary media interest and confirms the alternatives considered before recommendation.'

4. Claims and approval authority

Name who supplies substantiation, who may change creative or destination pages and who can stop release. CAP Code section 3 covers substantiation, qualifications, prices and comparisons in UK non-broadcast advertising. The contract should support the approval workflow without pretending an indemnity prevents a misleading ad.

Sample wording: 'The advertiser approves creative and destination pages before release, and the agency supplies substantiation on request.'

5. Data instructions and suppliers

Attach the intended purposes, data types, role allocation, processors, retention and rights route. The ICO's direct marketing guidance sets out UK considerations whose application changes with the channel and recipient. Blanket labels should not replace analysis of each activity.

Sample wording: 'The agency processes personal data only on documented instructions and lists subprocessors, retention periods and rights routes.'

6. Security evidence and incidents

Define account access, authentication, logging, incident notice, investigation help and evidence preservation. The NCSC's SaaS security guidance (accessed 5 September 2026) supplies questions for UK organisations, not a warranty that a named system is safe. Link each obligation to the proposed setup and responsible party.

Sample wording: 'The agency notifies the advertiser of any security incident without undue delay and preserves relevant logs.'

7. Audit, termination and handover

Specify the records an auditor may inspect, notice periods, retention and treatment of confidential third-party material. At exit, list accounts, tags, audiences, creative, orders, invoices, reports and configuration that must be returned or transferred. The GOV.UK advertising law overview shows why campaign records may span accuracy, direct marketing and sector duties.

Set a handover timetable while access still exists.

Worked handover timetable:

Sample wording: 'On termination the agency returns or transfers accounts, tags, audiences, creative, orders, invoices, reports and configuration.'

Decision record

Mark every answer as contract wording, supporting schedule, supplier statement or unresolved point. Do not score a missing answer as if it were a poor answer; send it back. Sign only after the commercial owner, privacy and security reviewers, and qualified English-law adviser have resolved the matters that fall within their remit.

Before you act

Common questions

What should the contract say about the contracting entity?

See matter 1. Ask for the legal name and company number to appear on the proposal, insurance, purchase order and invoice.

How should remuneration and money flow be set out?

See matter 2. Separate agency remuneration from pass-through media and technology costs, and reconcile both to invoices.

What must be settled for audit, termination and handover?

See matter 7. Agree the audit scope and exit asset list before access is withdrawn.