The short answer
If a client hasn’t paid your invoice, don’t immediately assume they are refusing to pay.
First, confirm that the invoice was received, approved, and sent to the right person. Then identify the person who actually owns payment—often someone in finance, accounts payable, or procurement—and get a specific payment date.
If that date passes, follow up immediately and escalate through the client organization rather than repeatedly sending the same reminder to your original contact.
For agencies, this distinction matters. An unpaid invoice is often less a collections problem than an ownership problem.
1. Check whether the invoice is actually payable
Before sending another “just following up” email, check four things:
Was the invoice sent to the correct billing address?
Does the client require a PO?
Has the work or milestone been formally approved?
Is the invoice already entered into the client’s payment system?
A perfectly valid invoice can sit unpaid for weeks because one administrative step was missed.
2. Stop asking only your project contact
Your day-to-day client may genuinely have no ability to release payment.
If they tell you:
Finance is handling it.
Your next question should be:
Great—could you connect me with the person handling this invoice so I can follow up directly?
That changes the conversation.
You are no longer asking someone to “please pay.” You are finding the operational owner.
3. Ask for a date, not an update
Compare:
Any updates on payment?
with:
Could you confirm the expected payment date for invoice #184?
The second is much harder to answer vaguely.
Once a date is promised, record it.
If the money does not arrive, follow up against that commitment:
We had payment scheduled for September 8, but it hasn’t reached us yet. Could you check what is holding it up?
4. Move beyond email when necessary
If several emails produce no progress, call.
A five-minute conversation can uncover what ten email reminders do not:
a missing PO
an absent approver
incorrect vendor details
an invoice rejected by the system
a payment batch scheduled for a later date
The goal is not to become more aggressive. It is to find the blocker.
5. Decide when founder involvement is actually necessary
For a small agency, the founder should not have to personally manage every reminder.
Founder authority is useful when:
the client disputes the work;
the client explicitly refuses payment;
commercial leverage needs to be used;
future work may need to stop.
Everything before that can be treated as payment operations.
What if the client is simply ignoring you?
A client going silent is a stronger warning sign.
Use a clear escalation sequence:
Follow up with your main contact.
Contact finance/AP directly.
Copy the relevant decision-maker.
State the amount, due date, and previous promised payment date.
Explain what will happen next if payment remains unresolved.
Avoid emotional language. The more serious the situation becomes, the more factual your communication should become.
FAQ
How long should I wait before chasing an unpaid invoice?
You do not need to wait. If the invoice is due today, it is reasonable to confirm payment today or the next business day.
Should I keep working if an invoice is overdue?
That depends on the amount, relationship and contract, but you should have a predetermined point at which new work pauses rather than making the decision emotionally each time.
What if the client says accounts payable is processing it?
Ask for the AP contact, confirmation that the invoice has been approved, and the scheduled payment date.
Can someone else chase invoices for my agency?
Yes. Payment follow-up can be separated from the client relationship itself. Collected42 acts as an external payment-operations function for small agencies, handling the payment thread while the founder stays focused on the client relationship.