Why invoice custom fields become a sales problem
A business buyer may happily place an order but later refuse payment because the invoice lacks their PO number, project reference, or invoice email. Support then has to regenerate PDFs, edit templates, or send manual corrections.
Lattice Invoices is being shaped for that workflow: capture custom invoice fields once, keep them attached to the order and invoice record, expose them on PDFs and customer downloads, and include them in accountant-ready exports.
Custom invoice field readiness checklist
1. Decide which fields are invoice evidence, not just checkout notes
B2B buyers often enter VAT ID, PO number, department, cost centre, project code, delivery reference, and invoice email. These fields should travel from checkout to order, invoice PDF, customer download, and accountant export.
Buyer question: Does the invoice plugin store custom fields as structured invoice metadata instead of free-text order notes?
2. Show the right custom fields on the PDF template
A PO number hidden in wp-admin does not help the customer. The PDF should place buyer references in predictable invoice sections without breaking VAT totals, reverse-charge wording, or credit-note formatting.
Buyer question: Can the PDF template expose custom fields without manual PDF editing after every order?
3. Preserve field values on refunds and credit notes
If the invoice is corrected later, the credit note should keep the same buyer reference, PO number, VAT treatment, and original invoice link so accounting can match the documents.
Buyer question: Do credit notes inherit and link the relevant invoice custom fields?
4. Make fields searchable and exportable
Custom invoice data becomes useful when finance can search by PO number, filter B2B orders needing review, and export fields alongside invoice number, VAT rate, totals, PDF URL, and payment status.
Buyer question: Will the accountant receive these custom fields in CSV/export rows?
5. Validate required fields by customer type
A B2C customer should not be blocked by a PO field, while a B2B net-terms buyer may require PO number, invoice email, and VAT ID before the order can become invoice-ready.
Buyer question: Can the workflow require fields only for the buyer types that need them?
Three custom-field scenarios to test
Corporate buyer needs a PO number on every invoice
Trigger: A procurement team refuses to pay invoices unless the PDF includes their purchase-order reference.
Workflow: Capture PO number at checkout or admin review, store it on the invoice record, print it in the PDF header, include it in reminders, and export it for reconciliation.
Agency client needs project and cost-centre references
Trigger: A B2B client orders several services or plugins and wants the invoice booked to the right internal budget.
Workflow: Attach project code and cost centre to the order, preserve them through final invoice, credit notes, customer downloads, and accountant handoff.
VAT-exempt or reverse-charge orders need review notes
Trigger: A valid VAT number or exemption reason must be visible for finance before invoice PDFs are issued.
Workflow: Store validation state and review notes as invoice metadata, show the correct reverse-charge wording, and keep the evidence available for audit trail exports.
Weak custom fields vs invoice-ready metadata
| Weak workflow | Lattice Invoices direction |
|---|---|
| Custom checkout fields are saved as order notes that never appear on the invoice PDF. | Buyer references become invoice metadata that can print on PDFs, customer downloads, reminders, credit notes, and exports. |
| Admins manually edit PDF templates or email text when a PO number is missing. | Field rules make B2B invoice references required before the order is treated as invoice-ready. |
| Refunds and corrections lose the original project, PO, and VAT review context. | Credit notes preserve the original custom-field trail and link back to the corrected invoice. |
| Accountant exports include totals but not the custom fields finance uses to reconcile invoices. | Exports include invoice number, order ID, VAT metadata, payment state, PDF link, PO number, project code, and review status. |
FAQ
Can WooCommerce invoice PDFs include custom checkout fields?
Yes, but the important question is whether the field is treated as structured invoice metadata. A plugin should carry the field from checkout to order, PDF, customer account, credit note, reminders, and export rows.
Which custom invoice fields matter most for B2B stores?
The common fields are VAT ID, PO number, invoice email, buyer reference, cost centre, project code, delivery/reference number, exemption reason, and finance review notes.
Should a PO number be required during checkout?
Only for buyer types that need it. A good workflow lets stores require PO numbers for B2B, net-terms, quote, or manual-invoice flows without blocking normal consumer checkout.
Where does Lattice Invoices fit?
Lattice Invoices early access is aimed at WooCommerce stores that need EU VAT/BTW invoice workflows with structured metadata: VAT fields, PO numbers, invoice PDFs, credit notes, customer downloads, reminders, and accountant exports.