First find the specific reason for rejection
A rejected invoice may be missing a purchasing reference, use the wrong billing details, disagree with the order or have reached the wrong submission channel. Ask accounts payable for the rejection reason and required next step before changing anything. Distinguish an administrative rejection from a dispute about the work: a payment reminder alone will not resolve either problem.
Check these fields against the customer’s instructions
Keep the rejected PDF and rejection message together. Compare them with the accepted quote, purchase order and supplier-onboarding instructions. Customer requirements differ; this is a diagnostic checklist rather than a universal invoicing rule.
- Billing entity and address: do they match the customer’s requested details?
- Purchase order: is the exact customer-issued reference present and valid for this work?
- Invoice number: is it unique in your records, or has this invoice already been submitted?
- Scope, quantities and rates: do they match the accepted order and delivery?
- Currency, totals and payment amounts: do they agree across the PDF and supporting documents?
- Delivery channel: does the customer require a portal or a particular accounts-payable address?
Missing purchase order: ask the buyer, do not invent one
Your invoice number and the customer’s PO number serve different purposes. Ask your purchasing contact for the correct PO or their documented exception process. Creating your own purchase order in a generator does not create approval inside the customer’s system. For example, the UK Department for Work and Pensions publishes a No Purchase Order, No Pay policy requiring its valid PO reference. That is a specific buyer policy, not a rule for every customer.
Worked example: the missing reference
Suppose INV-2026-057 bills an agreed USD 600 design milestone, but the customer returns it because PO-118 was omitted. First confirm that PO-118 covers that milestone. Ask whether they need a corrected document or only a reference added in their portal. Preserve the original and follow the applicable correction process. Do not issue a second collectible USD 600 charge to bypass the rejection.
Invoice reference: INV-2026-057 Customer purchase order: PO-118 Work: Homepage design — approved final milestone Quantity: 1 Rate: USD 600 Amount: USD 600 Record internally: returned for missing PO reference; corrected document or portal update supplied on [date].
When the amount or work is disputed
Compare each disputed line with the agreement and delivery evidence. If the buyer says the order is exhausted, do not split or rename the same charge simply to make it pass their checks. Get clarification or an approved scope change from the authorized buyer. If a price or tax correction is needed, the required document process depends on your circumstances; retain the original and any formal adjustment.
Email template: ask for the missing information
Keep the question narrow so the recipient can answer it. Reference the rejected invoice without assuming that an accounts-payable employee can approve extra work or change your agreement.
Subject: Information needed to resubmit invoice [number] Hi [name], Invoice [number] for [currency and amount] was returned with the reason “[rejection reason]”. Could you confirm [the correct PO / billing entity / required submission channel] and whether you need a corrected invoice or an update to the existing submission? I will keep the original reference in our correspondence so the resubmission can be matched without a duplicate charge. Thank you, [your name]
Resubmit once and retain the acknowledgement
After correcting the identified issue, recheck the entire PDF. Include the rejection reference or portal case number where requested. Save the upload acknowledgement or sent email, and ask whether the invoice is now accepted for processing. Acceptance is not proof of payment. Confirm the expected payment date with the customer rather than silently resetting the agreed due date.
What this tool can and cannot resolve
Free Invoice Generator can help you edit descriptions and references and download a reviewed PDF. It cannot inspect a customer’s PO system, submit to their portal, approve an invoice or reconcile incoming payments. Keep the customer’s acknowledgement alongside your own saved records.