Three signs a marketing agency is overbilling you

Most contractors discover an agency was overbilling about a quarter after the contract ended. The reason it takes that long is structural: the invoice line items are written in a vocabulary the contractor does not own, and the dashboard is configured by the same team being paid. Three signs catch the pattern early enough to renegotiate or leave.

Sign one: the monthly retainer covers “management” of an ad spend the contractor cannot itself verify.

The standard contractor retainer arrangement is a flat monthly fee plus a separate ad-spend budget. When the agency manages the spend and refuses read-only access to the underlying Google Ads or Meta Ads account, the contractor cannot independently verify what was bought. The Federal Trade Commission’s Endorsement Guides require any party making efficacy claims to be able to substantiate them; the same standard should apply to invoiced media buys. [source: FTC Endorsement Guides FAQ, accessed 2026-05-20; https://www.ftc.gov/business-guidance/resources/ftcs-endorsement-guides-what-people-are-asking] A contractor should always own the platform login.

Sign two: leads delivered are not unique to the contractor.

Shared-lead arrangements (the same homeowner inquiry sent to three or four contractors at once) inflate the apparent lead count without inflating the contractor’s win rate. HomeAdvisor’s 2023 settlement with the FTC named exactly this practice. [source: FTC press release, January 23, 2023; https://www.ftc.gov/news-events/news/press-releases/2023/01/ftc-order-requires-homeadvisor-pay-72-million-stop-deceptively-marketing-its-leads-home-improvement] If the invoice line says thirty leads and the dashboard says thirty leads, but the close rate is under five percent, the leads are almost certainly being sold downstream. A contractor-exclusive lead outperforms a shared lead at the same nominal price.

Sign three: reporting language hides the conversion gap.

Honest reporting names three numbers: cost per lead, cost per booked appointment, cost per signed job. Agencies that report only “cost per lead” or only “impressions” are choosing the metric that flatters their work. Ask for cost per signed job on every monthly call. If the agency cannot produce it, the agency does not know whether its work is profitable for the contractor.

The single defensible test: can the contractor turn off the agency for one month and watch the pipeline. If new jobs stop, the agency is doing work. If new jobs continue, the contractor was paying for activity, not outcomes.