Start from the problem, not the feature list
Sell to companies that require purchase orders
Large customers pay reliably and slowly, and only if the invoice matches a purchase order they issued. A missing PO number is not a mistake to them; it is a reason to reject the invoice and restart the clock.
The situation
You landed a corporate or public-sector customer. Their process is fixed: a PO first, an invoice that quotes it, delivered to accounts payable (not to the person you worked with), and often through a vendor portal or an e-invoicing network.
What goes wrong today
The invoice goes to your contact, who forwards it late or not at all. The PO number is missing or the amount exceeds the PO, and the rejection arrives three weeks later. You find out when the payment does not.
How it works in Invoice My Clients
Record the customer's purchase order and invoice against it (Business plan). Two-way and three-way matching checks the invoice against the PO and the receipt before it goes out, with the tolerances you allow; the No-PO-No-Pay block stops an invoice without a PO for customers who require one. Add the accounts payable contact and the signer to the client so invoices and reminders go to the people who pay. Where the customer requires e-invoicing, deliver through the Peppol or DBNA networks. Attach the vendor setup kit (W-9, insurance certificate, remittance details) so onboarding does not stall.
When it does not fit
| Situation | What happens | What you do |
|---|---|---|
| The customer uses a vendor portal (Ariba, Coupa) | There is no portal integration | Upload the PDF to their portal; the PO number and matched amounts are already on it |
| You are on Professional or below | Purchase orders and e-invoicing are on Business and above | Type the PO number into the invoice reference and send to the AP contact |
| The PO amount is lower than the work done | Matching flags the overage | Ask for a PO amendment before sending, or split the invoice |
| The customer sends you a PO as a PDF | Business plan: the AI drafts the PO from the PDF for you to confirm | Review the draft and link your invoice to it |
Where this lives in the product
Free tools
Questions people ask
Do I need the customer to be on Peppol?+
Only if they require e-invoicing. Otherwise email, the client portal or mail work as usual.
Can reminders go to accounts payable instead of my contact?+
Yes. Set the AP contact on the client; reminders widen to AP and the signer on the Professional plan and above.
What is three-way matching?+
Invoice, purchase order and receipt agree within the tolerance you set. The glossary entry explains it.