Marketing agency due diligence

A marketing agency has almost no hard assets to inspect, so diligence here is less about the balance sheet than about logging into the actual systems the agency runs and confirming who controls what. The findings that most often surface late, and most often change the price, trace back to platform account structure, media-spend reconciliation and undisclosed client notice, which is why a buyer’s diligence checklist for an agency should look meaningfully different from the checklist for a business with physical assets to count.

Audit the platform accounts directly, not the seller’s description of them

Ask for administrator-level access to every material client’s ad accounts, analytics property, content-management system and social channels, and confirm directly which entity — the client or the agency — actually owns each one, rather than accepting the seller’s summary that accounts are in good standing. An account the seller describes as client-owned can turn out, once actually inspected, to be registered under the agency’s own corporate details with the client simply listed as a user, which is a materially different asset to inherit.

Reconcile any media spend running through the agency’s own accounts

Where the agency pays media platforms directly and invoices the client afterward, get a current reconciliation of every account showing what has been spent, what has been invoiced, and what remains uncollected, because an uninvoiced or uncollected balance sitting inside the agency’s own media account is a real liability the buyer inherits at closing, not a rounding error. Ask, too, whether any platform has placed a spend limit or a credit hold on an agency-owned account, since that is often an early signal of a reconciliation problem the seller has not yet raised.

Confirm platform certifications and partner-status are institutional, not personal

Some ad platforms grant an agency preferred pricing, early access to features, or a partner badge based partly on staff holding current certifications, and it matters whether those certifications sit with several people at the firm or with one employee whose continued employment is not guaranteed. Ask which staff hold the certifications underlying any partner-status the agency advertises, and confirm what happens to that status if the certified individual leaves shortly after the sale.

Confirm freelance and contractor creative was actually assigned to the agency

Agencies routinely bring in freelance designers, copywriters, video editors and developers for client work, and diligence should confirm each of them signed an agreement assigning their intellectual property to the agency rather than leaving it with the individual contractor. Ask for the freelancer agreements behind the agency’s most-reused creative templates and portfolio pieces specifically, since a gap here is not just a client-facing risk — it can mean the case studies and reusable assets the buyer is counting on to win new business are not actually the agency’s to keep using. Where no written assignment exists, treat the underlying work as a liability until it is resolved, not as an asset already secured.

Check every retained-program contract for notice already given

Beyond reading contract terms for notice periods generally, ask the seller directly, client by client, whether any has already indicated an intention to cancel, downgrade or not renew a retained program, and confirm the answer against the agency’s own account-management notes rather than taking it on faith. A program that reads as active in the financial statements can already be functionally over if a client gave verbal notice weeks before the sale process began.

Data segregation across clients is its own finding

An agency running email, retargeting and customer-list campaigns for multiple clients often holds several clients’ customer data and consent records inside its own marketing and analytics tools, and diligence should confirm that data is actually segregated by client — including consent records for commercial electronic messages tracked separately for each client’s list rather than pooled into one master list the agency reuses — rather than commingled in a way that could breach a client’s confidentiality terms or create a shared breach-notification obligation if one client’s data were exposed. A buyer inheriting a poorly segregated data environment is inheriting an obligation under federal privacy and anti-spam law that follows the agency regardless of which client’s data was involved.

What a finding actually means once you have it

Not every finding here is disqualifying — an agency-owned account with a modest reconciliation gap, or a certification tied to one employee, is common and can usually be addressed through a purchase-price adjustment or a pre-closing condition rather than treated as a reason to walk away. What matters is finding it before closing, while the buyer still has the leverage to require it fixed, rather than discovering an uninvoiced client balance or an undisclosed cancellation notice for the first time after the deal is done.

• Get administrator access to every material client’s accounts and confirm the actual owner of each
• Reconcile media spend, invoicing and collections on every agency-owned account
• Confirm platform certifications underlying any partner-status sit with more than one employee
• Ask client by client whether any has already given notice to cancel or not renew
• Confirm client data held in the agency’s own tools is segregated, not commingled