Quote to invoice workflow
Belgian commercial lifecycle from quote acceptance through delivery to Peppol invoice: gates, numbering, advances, and corrections without redefining document types.
Updated
- Belgium
Run the lifecycle as gates, not as document definitions
This article is the operating sequence: quote → acceptance → delivery → invoice → (optional) credit. It does not redefine what each document is. For roles and Peppol relevance, use Invoice, credit note, and quote. For field completeness on the invoice, use Mandatory legal mentions.
Most Belgian B2B VAT and Peppol failures come from skipping a gate or converting too early.
Lifecycle map
| Gate | Done when | Output you keep | Peppol? |
|---|---|---|---|
| 1. Quote | Offer sent with validity + clear scope | Quote ID in a non-invoice sequence | No |
| 2. Acceptance | Written yes / PO / portal confirm logged | Acceptance date + PO ref | No |
| 3. Delivery | Goods shipped or milestone signed off | Delivery / timesheet evidence | No |
| 4. Invoice | Issued against actual supply (or valid advance) | Invoice number + structured payload | Yes when mandate / buyer requires |
| 5. Correction | Amounts change after send | Credit note linked to invoice | Yes (same rail as invoice) |
Gate discipline that scales
Acceptance before conversion. A verbal "go ahead" is not enough for disputes. Log who accepted, when, and any PO. Acceptance alone still does not replace an invoice: a deposit due on signature needs an advance invoice, not a relabelled quote.
Invoice what was delivered. Convert from accepted quote + delivery data. If scope drifted, update the commercial trail (revised quote / change order) before issuing. Material mismatches between quote lines and invoice lines create AP rejection and audit noise.
Peppol only at invoice (and credit note). Quotes stay in email, PDF, or CRM. From 1 January 2026, many domestic Belgian B2B invoices must go structured over Peppol; do not wait until you have months of non-compliant PDF "invoices" in the wild. See the Belgian e-invoicing obligation (2026).
Numbering across the pipeline
| Document | Sequence habit | Anti-pattern |
|---|---|---|
| Quote | Prefixed commercial codes (Q-2026-0042) | Sharing the invoice counter |
| Invoice | One gap-free series per legal entity | Editing / renumbering after send |
| Credit note | Separate series, billing reference to invoice | Informal email discount |
Belgian teams often keep quotes visually distinct (Q-… vs 2026/0042) so finance and clients see which document is VAT-binding.
Advance and partial billing
| Pattern | When to use | Watch-out |
|---|---|---|
| Advance invoice | Deposit on acceptance | It is an invoice (VAT timing rules apply), not a quote |
| Milestone / partial invoice | Contract allows progressive billing | Align lines to signed milestones |
| Final invoice | Remaining balance after completion | Deduct advances already invoiced; do not re-invoice the full quote |
After send: credit, do not rewrite
Once an invoice is issued (especially on Peppol), amounts change only via a credit note and, if needed, a corrected invoice. Silent PDF edits break buyer open items and VAT returns. Details: Credit notes on Peppol.
Minimal runbook
- Issue quote with validity and scope
- Log acceptance + PO
- Confirm delivery internally
- Generate invoice from acceptance + delivery (not from stale quote alone)
- Send via Peppol when the obligation or buyer requires it
- Correct with credit note + re-issue, never by editing history
OrdoGrid converts quotes without re-keying while keeping document types and numbering rules separate, so identical commercial lines still carry the right legal status.
- Tax invoice
Formal billing document that records a supply, claims payment, and serves as primary VAT evidence for VAT-liable businesses. Distinct from a quote or pro forma.