Invoices and documents · 5 min read

Proforma invoices and final invoices

When and how to issue a proforma invoice in Taxorio, how to link a final tax document deducting the advance to it, and what the effects on the VAT return are.

What a proforma invoice is

A proforma invoice is a request for an advance payment before the actual supply takes place. It serves as the basis for the payment, but on its own it's not a tax document — a non-VAT payer can use it with no restrictions, but a VAT payer must issue a tax document for the received payment once the advance arrives.

This article covers the issuing side — advances you receive from your own clients. Advances that you pay to your own suppliers are covered in Advances you pay to suppliers.

💡 Tip: Proforma invoices are typically used for larger jobs (web projects, construction work, deliveries of goods) where you want to secure the payment up front.

When to use a proforma invoice

  • The job runs into the tens of thousands of CZK and you want to reduce the risk of non-payment.
  • The supply will take a while (a 2–3 month project) and you need staged payments.
  • The client wants a proforma invoice as the basis for internal payment approval.

How to issue a proforma invoice in Taxorio

  1. Go to the Invoices section and click New invoice.
  2. Above the form, switch from Standard invoice to Proforma invoice.
  3. Pick the client, enter a description of the advance (e.g. "50% advance for website development") and the advance amount.
  4. For VAT payers: choose the relevant VAT rate — the advance is subject to VAT at the same rate the final supply will carry.
  5. Save and send it to the client by email.

Confirming a received advance

  1. Once the money arrives, open the proforma invoice's detail and click Advance paid (the dialog asks for the date the payment was received).
  2. VAT payer: a tax document for the received payment is created (DDZ sequence) with its date of taxable supply (DUZP) set to the payment date — it goes into the return and the VAT control statement.
  3. Non-payer, flat-rate taxpayer, identified person: no tax document is created (§ 108 odst. 4 ZDPH doesn't allow it) — the proforma invoice is simply marked as paid and it carries the income itself.
⚠️ Confirming always processes the full amount of the proforma invoice. Partial payments, several staged payments, or an "undetermined" advance (where what will be supplied, and at what rate, isn't clear yet) aren't supported by Taxorio — work those cases out with your accountant.

Recorded the payment by mistake, or with the wrong date? On the proforma invoice's detail, use More actions → Clear payment. The proforma invoice goes back to unpaid and the tax document for the received payment is cancelled; then you confirm the advance again with the correct date. The payment date can't be rewritten by editing — it's tied to the tax document's DUZP.

Final invoice deducting the advance

Once the goods or service are delivered, issue a final invoice — always from the detail of the paid proforma invoice, using the Issue final invoice button. That's the only way the document stays linked to the right advance.

  1. Open the paid proforma invoice's detail and click Issue final invoice.
  2. The form pre-fills the items from the proforma invoice — it's the same supply. If you're invoicing for more than the advance covered, add another item; don't overwrite the pre-filled one.
  3. Taxorio calculates the advance deduction on its own — a locked row appears among the items that can't be edited or deleted. For a VAT payer it's deducted per the tax document for the payment (by rate); for a non-payer, the advance amount actually paid is deducted directly.
  4. Save. The client only pays the difference — and if the advance covered the whole price, the final invoice comes to CZK 0 due. That's the correct outcome; the document serves as proof the supply took place.
ℹ️ Each advance can have only one active final invoice at a time; once it's cancelled, a new one can be issued. Only the balance due (the rest was already covered by the advance) enters income from the final invoice — the full price of the job is visible in the items.

VAT on an advance — important for VAT payers

A VAT payer is legally required to declare VAT on received advances. Specifically:

  • The moment the advance is received the obligation to declare VAT arises, along with 15 days to issue a tax document for the received payment.
  • Confirming the payment with the Advance paid button makes Taxorio issue the VAT payer a tax document for the received payment (DDZ sequence) right away — it doesn't ask, it's a legal obligation. The document enters both the VAT control statement and the VAT return.
  • The advance enters the VAT return for the tax period in which it was paid.
  • On the final invoice the advance (VAT included) is deducted — only the difference then enters the VAT return.
⚠️ Careful: A proforma invoice without a received payment doesn't enter the VAT return. The VAT obligation only arises once the payment is received, not when the proforma invoice is issued.

When something goes wrong — what to correct

  • Payment never arrived / wrong date → Clear payment on the proforma invoice (this also cancels the tax document for the payment), then confirm it again.
  • Money is being refunded and there's no final invoice yet → a credit note against the tax document for the advance, after which the proforma invoice can also be cancelled.
  • The final invoice already exists → the tax document for the advance can't be corrected any more (the action is locked). Price changing → a credit note against the final invoice for the whole supply. Supply never happened → cancel the final invoice first, only then correct the advance.
  • A paid advance or final invoice can't be edited — a paid document simply can't be edited in Taxorio.
  • Not a VAT payer and refunding an advance? You never had a tax document for the payment, so there's nothing to credit-note — clear the payment and cancel the proforma invoice. Watch out for the year: clearing the payment removes the income from the period the advance arrived in. If you're refunding it in a later year, once the earlier return is already filed, work it through with your accountant — you'd otherwise be rewriting a closed year yourself.

More detail in the article Credit notes and corrective documents.