The pro forma invoice is one of the many types of invoices that can be issued in Spain. However, it is the only one that is not valid for tax purposes. Therefore, businesses need to know when to use it—whether as a draft for finalizing commercial agreements or as an informational document for exports.

In this article, we explain pro forma invoices, including what they are used for and how to manage them without administrative errors.

Key takeaways

• Pro forma invoices are drafts of regular invoices that inform customers of upcoming transactions.
  
• They are not valid for tax purposes, but they can be legally valid.
  
• Pro forma invoices serve multiple purposes, such as expediting customs clearance procedures, making business offers, and validating data.
  
• They can be converted into tax-valid invoices by following a series of steps.
  

What is a pro forma invoice?

A pro forma invoice is a commercial document that provides the customer with information about a future transaction. Generally, the pro forma invoice is issued after the quote and before the final invoice.

Pro forma invoices are commonly used as drafts or sample invoices in businesses such as restaurants and those that invoice foreign customers. These businesses use pro forma invoices to inform customs officials of the value of goods.

Validity of pro forma invoices in Spain

When businesses issue pro forma invoices, they need to know when these documents are valid to avoid misunderstandings with customers and administrative issues. Below, we explain the validity of pro forma invoices.

Not valid for tax purposes

Unlike other invoice types, pro forma invoices are not valid for tax purposes. The Spanish government has explicitly stated this in several official publications—such as this Official State Gazette (BOE) from January 2024 regarding local grants—clarifying that pro forma invoices are not accepted as proof of expenditure. This lack of validity for tax purposes means they cannot be used to settle taxes with the Spanish Tax Agency (AEAT) or provide proof of deductible expenses.

Although a pro forma invoice generally indicates the price of a sale—and often the taxes associated with the transaction—it does not require the recipient to pay the amount.

Legally valid when signed

Pro forma invoices become legally valid when customers sign them. Despite being informational documents with no tax implications, they can entail legal consequences. For this reason, it is common for the Spanish government to recommend their use. For example, the European Consumer Centre in Spain (CEC-Spain) advises requesting a pro forma invoice before completing a trip.

What are pro forma invoices used for?

Although they are not valid for tax purposes, pro forma invoices have various commercial uses, making them an indispensable tool for many Spanish businesses. Here are their main uses.

Expedite exports

Providing a pro forma invoice is one of the requirements for exporting from Spain that applies to certain transactions, such as the delivery of free samples. It is also common to include pro forma invoices so customs officials can verify important details, such as declared values.

There has been significant international expansion of Spanish businesses. For example, goods exports totaled nearly €34.7 billion in May 2026, according to the Spanish Ministry of Economy, Trade and Business. Therefore, it is common practice in Spain to use pro forma invoices to describe the goods being transported and help facilitate customs control procedures.

Validate data

A pro forma invoice is typically provided to a customer as a draft so they can verify the entered details. Once verified and confirmed by the customer, the business issues the final invoice. By allowing the customer to verify data, businesses can avoid invoice errors that necessitate the issuance of corrective invoices.

Such inaccuracies have become increasingly rare because electronic invoicing requires less manual intervention. In Spain, electronic invoicing will become mandatory once the final regulations of the Create and Grow (Crea y Crece) Law are approved.

Make business offers

On pro forma invoices, businesses detail the prices of products or services, along with descriptions and key aspects that customers must validate to accept business offers. Unlike a quote, a pro forma invoice contains more than estimates. Instead, it reflects the final terms of the commercial agreement.

Process reservations or customized orders

To process reservations for certain types of services—such as customized orders—firm commitments from customers are required. In some cases, businesses use pro forma invoices as evidence of customer commitment. While the document does not strictly constitute an obligation, it transparently sets out the terms of the agreement reached by both parties.

Obtain financial assistance or subsidies

Sometimes, banks and lending institutions require documentation that verifies the costs of products or services to grant financial assistance. Pro forma invoices provide the information needed to approve financing transactions, which have become increasingly common in Spain. In 2025, self-employed individuals received more financing than in the previous year, according to data from the 2025 Report of the Central Credit Register.

On the other hand, pro forma invoices can also be useful when applying for certain types of aid—such as grants for starting businesses in Spain—as they provide proof of the ways requested funds will be used.

How to create a pro forma invoice

Pro forma invoices are not subject to strict formal requirements. However, it is advisable to follow certain guidelines so the documents fulfill their informational purposes and can be easily converted into final invoices. Below, we explain the most common fields and how to transform a pro forma invoice into an invoice valid for tax purposes.

Content to include on pro forma invoices in Spain

The content of pro forma invoices is typically identical to that of final invoices. Businesses can prepare pro forma invoices with considerable flexibility because they are not subject to strict mandatory billing information. However, when used in the export process, pro forma invoices must meet certain requirements to be valid as documents that verify transaction data.

We have prepared a list of the necessary details that must be included on pro forma invoices so businesses can use them to document sales abroad:

• Legal notice: It is mandatory to include the label “pro forma invoice” in the header to explicitly indicate that it is not a final invoice.
  
• Date: This is the date the invoice is issued (i.e., when it is prepared and sent).
  
• Issuer details: This field must include the issuer’s name, address, and tax address, as well as the intracommunity VAT number (NIF-IVA), if exporting to another EU member state, such as France.
  
• Customer details: The name, address, and tax address of the purchasing party must be included.
  
• Description: It is mandatory to describe the goods and specify the units being transported.
  
• Amount: The unit price and final price must be stated; the latter generally does not differ from the price shown on the final invoice.
  
• Packages: This indicates the number of packages being transported, as well as their weight and volume.
  
• Additional costs: If the business is covering transport and insurance costs, this must be included on the pro forma invoice.
  

Conversion of pro forma invoices into tax-valid invoices

Current regulations do not specifically govern pro forma invoices. In practice, pro forma invoices typically include almost the same information as regular invoices. However, these similarities do not make pro forma invoices the same as invoices valid for tax purposes. For pro forma invoices to acquire full validity for tax purposes, the following conversion process must occur.

Remove or amend the wording

First, remove the wording “pro forma invoice,” or replace it with the appropriate wording, depending on the type of invoice. For example, if a customer from the US accepts an offer, the business must replace the term “pro forma invoice” with “invoice” so the document is clearly identified as a regular invoice.

In addition, it can be necessary to include other statements. For example, the invoice might need to include a specific statement detailing the reason for a value-added tax (VAT) exemption, such as the application of Article 21 of Spanish Law 37/1992.

Add or amend the numbering

Pro forma invoices do not have to be numbered. If they are, it is only for internal control purposes. However, numbering is one of the most important pieces of information on the final invoice. An invoice must have a number—and, optionally, a series—that identifies it in sequential and chronological order.

Change the date

If the issue date of the pro forma invoice does not match that of the final invoice, update it to accurately reflect when the transaction or advance payment occurred.

Record the invoice

Before recording the document and converting it into a regular invoice, verify the tax information, such as the Tax Identification Number (NIF) and itemized VAT. This step requires no manual intervention if the business uses Stripe Tax, a tax automation tool that automatically applies VAT rates in Spain and other countries to calculate and collect taxes on Stripe transactions.

How Stripe can help manage pro forma invoices

Properly managing pro forma invoices is important because they become legally valid when customers accept or sign them. In many cases, businesses give these documents to potential customers, so it is important to avoid errors when processing them. This can help build trust and increase revenue.

To expedite the issuance of pro forma invoices, the Stripe App Marketplace offers access to an extensive library of invoicing tools. For example, Invopop allows you to assign the “pro forma invoice” label to invoices. Once received, your customers can accept or reject them directly, which expedites formalization of agreements. In addition, Billit is an electronic invoicing platform that also supports the creation of pro forma invoices.

Pro forma invoices serve as the basis for the subsequent issuance of final invoices. To avoid problems—such as penalties from the AEAT or complaints from customers—it is important to verify that all data entered is correct. This can be achieved by limiting or eliminating manual transfer of information. Automated payment platforms—such as Stripe Payments—can eliminate manual tasks in all processes of invoice issuance, collection, and payment reconciliation.

FAQs about pro forma invoices