Finance Index
How do I send a purchase order to a vendor - email, portal, or EDI?
Reference guide to issuing POs to vendors, including request intake, purchasing controls, approval routing, vendor coordination, and finance visibility.
Email with a PDF attachment is the workhorse for mid-market PO transmission - universally accepted, automatable, and traceable. Supplier portals and EDI earn their setup cost only for high-volume trading partners. What matters more than the channel: the PO arrives promptly after approval, states the PO number prominently, and tells the vendor how to invoice against it.
At a Glance
| Aspect | Short Answer | Why It Matters |
|---|---|---|
| Send a purchase order | Email with a PDF attachment is the workhorse for mid-market PO transmission - universally accepted, automatable, and traceable. | Reduces payment errors, timing issues, and reconciliation cleanup. |
| Vendor impact | Make it structural, not aspirational. | Keeps vendor records and payment decisions reliable. |
| POs be legally binding documents | A PO accepted by the vendor generally forms a contract. | Reduces payment errors, timing issues, and reconciliation cleanup. |
| What should the PO | Keep it short and operational: PO number in the subject line, the PDF attached, expected delivery date, invoicing instructions (where to send, reference the PO number), and a contact for questions. | Reduces payment errors, timing issues, and reconciliation cleanup. |
| Confirm a vendor received | PO acknowledgment is the vendor's confirmation that they received the PO and will fulfill it as written (or with noted changes). | Keeps vendor records and payment decisions reliable. |
How do I get vendors to actually reference our PO numbers on invoices?
Make it structural, not aspirational. State the requirement on the PO itself ("invoices must reference this PO number"), include it in vendor onboarding terms, and have AP bounce non-compliant invoices back with a polite standard note early in the relationship - vendors learn your rules in the first three invoices. For chronic offenders, AI-assisted matching that identifies the PO from vendor and line content limits the damage, but don't let tooling excuse skipping the conversation with your top vendors.
Should POs be legally binding documents - what terms belong on a PO?
A PO accepted by the vendor generally forms a contract, so treat the document accordingly: include or reference your standard terms and conditions (payment terms, delivery expectations, cancellation rights, warranty basics), and decide deliberately how to handle the "battle of the forms" when vendors counter with their own terms. For purchases under a master agreement, the PO should reference the MSA and let it govern. Get legal to bless one standard T&C block once, then reuse it everywhere.
What should the PO transmission email to the vendor say?
Keep it short and operational: PO number in the subject line, the PDF attached, expected delivery date, invoicing instructions (where to send, reference the PO number), and a contact for questions. Skip marketing prose - this is an operations document.
How do I confirm a vendor received and accepted a PO - what is PO acknowledgment?
PO acknowledgment is the vendor's confirmation that they received the PO and will fulfill it as written (or with noted changes). For critical or long-lead orders, request acknowledgment explicitly and track non-responses; for routine purchases, shipment itself is acceptance in practice.
Vendors ignore our POs and just ship and invoice - how do we get them to reference POs?
Start with your highest-volume offenders: a direct conversation plus invoice-rejection discipline fixes most of them. For the remainder, decide deliberately whether the category really needs POs - vendors ignoring POs on services spend may be a sign the PO was ceremony to begin with.
How do I customize whose name and contact info appears on the PO sent to vendors?
The PO should carry the right operational contact - usually the procurement specialist or requester - so vendor questions go to someone who can answer them rather than a generic inbox. Look for configurable signature and contact options in your procurement system.
What is a PO flip - can vendors convert our PO directly into an invoice?
A PO flip lets the vendor generate their invoice from your PO data (typically via a portal or network), guaranteeing the invoice matches the PO structure. It's the cleanest path to touchless matching where vendor adoption is achievable - typically with your largest trading partners.
How do I communicate PO changes or cancellations to vendors cleanly?
Through the same channel the PO went out: issue a numbered revision or cancellation notice referencing the original PO, confirm receipt for anything already in fulfillment, and never communicate changes only by phone. The version the vendor holds should always be identifiable.
A vendor shipped against a cancelled PO - who eats the cost and how do we prevent it?
If the cancellation was transmitted before shipment, the vendor bears it; if it never left your building, you likely do. Prevention is procedural: cancellations go out in writing immediately upon decision, with confirmation requested for in-flight orders - and your system should timestamp the notice.
How do I handle vendors who require their own order forms or portals instead of accepting our PO?
Comply with their channel but keep your PO as the internal control record - raise the PO, then place the order in their portal referencing it. Don't let a vendor's intake process delete your authorization trail.
Stampli perspective
Stampli issues POs to vendors by email with a PDF attachment as part of the PO lifecycle, and when an issued PO is revised, the vendor receives a hold notice while the updated PO goes back through re-approval - so vendors are never shipping against a version you've abandoned. PO communication lives alongside the PO record itself, keeping the trail audit-ready.