Accounts payable is not a traditional marketing topic. Which is exactly why marketers and sales / revenue operators can make it harder than it often needs to be.
If you’ve ever had a campaign go live late because a supplier wasn’t set up in time, lost a vendor relationship because an invoice sat in someone’s inbox for six weeks, or watched a quarterly budget close with confusion about what was actually committed versus paid, then you’ve felt the downstream effects of a broken AP process, even if you couldn’t name the cause.
This piece is not a guide for finance teams. There are plenty of those. It’s for the people on the commercial side of a business — marketing directors, heads of RevOps, demand gen managers, account executives — who interact with the AP process regularly but rarely understand it well enough to work with it effectively.
That gap costs time, money, and supplier goodwill. Here’s how to change that.
What the AP Process Actually Is
Accounts payable (AP) refers to the system a business uses to manage, validate, and pay money it owes to external suppliers and vendors. Every time marketing books an agency, commissions a freelancer, purchases a software subscription, or runs a paid media campaign through a third party, that spend enters the AP process at some point.
The core stages look like this:
Purchase order (PO) raised. Before a supplier can invoice, most businesses require a purchase order — an internal document that formally authorises the spend. In smaller businesses this may be informal or skipped entirely; in larger ones, no PO means no payment. Marketing teams that bypass this step, or raise POs retrospectively after work has already started, create friction and delay.
Goods or services received. Once the work is done or the product delivered, the business records that receipt. This matters because payment should only follow confirmed delivery — not simply the receipt of an invoice.
Invoice received and validated. The supplier sends an invoice. Finance then checks it against the PO and the receipt confirmation in a process called three-way matching — PO, receipt, and invoice must align. Discrepancies (wrong amounts, missing references, incorrect billing entities) cause the invoice to be queried or rejected, which delays payment.
Approval. Validated invoices go through an approval chain depending on their value. This is where most marketing spend gets held up — approvers are busy, thresholds aren’t clearly defined, or the right person is out of the office.
Payment. Approved invoices are processed and the supplier is paid, typically on agreed terms (30, 60, or 90 days from invoice date).
Finance owns this process. But marketing and sales generate most of the supplier relationships that feed into it.
Where Finance Responsibility Begins and Ends
Understanding this boundary matters if you want to stop accidentally making AP harder than it needs to be.
Finance is responsible for: validating that invoices are accurate and match what was ordered; ensuring payments are compliant with internal controls and regulatory requirements; managing payment runs and cash flow timing; maintaining the audit trail; and preventing fraud and duplicate payments.
Finance is not responsible for: knowing whether the work was actually good; chasing suppliers for correct invoice details; understanding why a purchase order was raised or what it was for; or deciding whether a spend should have happened at all.
That last part is important. By the time an invoice arrives in finance, the commercial decision has already been made. The AP team’s job is to process it correctly, not to evaluate it. If the PO reference is wrong, the invoice total is different from what was quoted, or the supplier name doesn’t match what’s in the system — that’s not finance’s problem to fix. It gets sent back, and the clock restarts.
The cleaner the information that comes in from the commercial side, the faster and smoother everything downstream moves.
What Marketers and RevOps Teams Get Wrong
Having worked across agency, in-house, and consultancy environments, I’ve seen the same friction points come up repeatedly on the commercial side.
Raising POs late or not at all. This is the most common one. A campaign kicks off, a freelancer starts work, an agency begins a project — and the PO comes three weeks later when the invoice arrives. At that point, finance has to either reject the invoice (delaying the supplier), process it without proper authorisation (creating a control breach), or ask marketing to retrospectively justify spend that’s already been committed. None of these outcomes are good.
The fix is simple: raise the PO before work starts, not after. If your business has a procurement or finance team, get them involved at the point of supplier selection, not at the point of billing.
Giving suppliers the wrong billing information. Suppliers invoice based on what they’re given. If you give them an incorrect company name, wrong VAT number, or an email address that doesn’t reach the AP team, the invoice will need to be reissued. This adds days or weeks to payment timelines and frustrates suppliers who have done nothing wrong. Keep a standard briefing note with the correct billing details and share it with every new supplier at onboarding.
Not confirming payment terms upfront. Marketing agencies and freelancers often assume 30-day payment terms. Many enterprise businesses operate on 60 or 90 days. If this isn’t agreed and communicated at the start of the relationship, you’ll spend time managing expectations later — and potentially risk the relationship if a supplier needed the cash sooner.
Approving spend verbally but not formally. A budget holder says yes to a campaign in a meeting. The brief goes out, the work happens, the invoice arrives — and there’s no paper trail of the approval. Finance can’t process it without one. Either the budget holder needs to formally approve the invoice (which takes time) or it gets held pending confirmation. Get commitments in writing, even if it’s just a confirmation email.
Not flagging changes to agreed scope. Supplier invoices should match what was ordered. If scope changed mid-project — extra deliverables, additional days, revised media spend — and the PO wasn’t updated, the invoice won’t match and will be queried. Update POs when scope changes, not when the invoice arrives.
The Part Sales Teams Play
Sales teams interact with AP less directly than marketing, but RevOps professionals who sit across both functions need to understand the connection.
Commission payments, sales incentives, and any external supplier costs tied to sales activity (data providers, events, tools) all flow through AP. The same principles apply: proper authorisation before commitment, accurate supplier details, agreed payment terms.
Where RevOps can add specific value is in the data layer. When marketing spend, supplier costs, and revenue data all live in clean, connected systems, the AP team can reconcile what was spent against what was generated. That’s valuable for budget reporting, ROI analysis, and future planning — but only if the spend data coming in from the commercial side is consistently coded, categorised, and complete.
In practice that means: consistent use of cost codes or budget lines when raising POs; clear cost centre attribution so spend is mapped to the right team or campaign; and timely submission of anything that needs to be accrued (recognised in the accounts before the invoice arrives).
Finance runs a month-end close. Commercial teams who submit purchase orders, flag accruals, and confirm receipt of services on time make that process faster and more accurate. Those who don’t create a scramble at the end of every month.
Making the Process Slicker: A Practical Checklist
If you manage supplier relationships on the commercial side, these habits will make a material difference to how smoothly the AP process runs — and how your suppliers experience working with you.
Before engaging a supplier: Confirm the correct billing entity, address, VAT number, and AP contact email. Share these with the supplier before work starts. Agree payment terms explicitly and document them.
Before work starts: Raise the PO. Get formal budget approval if required. Confirm the approval threshold — does this spend need sign-off above your level?
During the engagement: Update the PO if scope changes. Keep a record of what was commissioned and when.
On delivery: Confirm receipt of goods or services internally. Don’t wait for the invoice to land to acknowledge the work is done — finance needs that confirmation to process payment.
When the invoice arrives: Check it immediately against the PO. Flag discrepancies to the supplier straight away rather than letting the invoice sit. Route it to the correct approver with any context they need to approve quickly.
At month end: Flag any spend that has been committed but not yet invoiced (accruals). Finance needs to account for this even if the invoice hasn’t arrived.
The Bigger Picture
AP might feel like an administrative detail, the final step after the real work of marketing or sales has been done. But how efficiently a business handles its supplier payments has a direct bearing on the quality of relationships it can build with agencies, freelancers, and technology partners.
Suppliers who are paid late, chased for correct invoice details, or kept waiting on approval chains that nobody is managing tend to quietly deprioritise those clients. They’re less likely to stretch on scope, turn things around at short notice, or advocate for you when their capacity is stretched. Good supplier relationships are a commercial asset. The AP process either protects them or erodes them.
The finance team can only work with what the commercial side gives them. The better that input (accurate POs, clean invoice details, timely approvals, proactive accruals) the faster and smoother the process runs for everyone.
This isn’t really about understanding accounting. It’s about understanding that the decisions made at the start of a supplier engagement affect what happens at the end of it. Get that right, and most of the problems fix themselves.
