Two documents, two different roles
A proforma invoice is a formalized offer: you tell the client what what they've requested costs, but the document has no fiscal value and doesn't trigger VAT obligations. A tax invoice is issued after delivery or payment and enters both parties' accounting records.
When to use each
- Proforma: before starting work, when the client needs a clear amount for internal approval or an advance payment.
- Tax invoice: after delivering the service/product, or as soon as you collect the advance requested on the proforma.
Many small teams skip the proforma and issue the tax invoice directly, which complicates things if the amount changes along the way (scope creep, a negotiated discount, etc.).
What the flow looks like in Voltzzflow
- You create the project and the estimate for the client.
- You issue a proforma directly from the platform, with the same line items as the offer.
- When the client confirms or pays the advance, you turn it into a tax invoice through the Oblio integration, without retyping anything.
A wrong proforma takes five minutes to redo. A wrong tax invoice means a conversation with your accountant.
Bottom line
The proforma is for negotiation, the tax invoice is for accounting. Keeping the two separate saves you unnecessary corrections and credit notes. If you want to issue both without ever leaving Voltzzflow, the Pro plan includes full Oblio integration.