Do you know what to include on an invoice? When to add “retention”? What if you find a mistake in an invoice that you already gave away? When can you issue a simplified invoice or ticket? And what changes with VeriFactu, the new Spanish invoicing-software rules?

Find answers to these and other questions in this post.

What is an invoice?

An invoice is a document that records the delivery of a good or service. Legally, it has to be logged in an “invoice book”, and the documents must be kept for 5 years.

Invoices and tickets.

There are different types of invoices. The simplified invoice — the traditional “ticket” — only contains the information of the issuer, not the receiver.

To be able to offset an expense, one of the requisites is that the transaction is backed up with a valid invoice. A simplified invoice or ticket doesn’t contain enough information for the buyer to deduct the VAT or justify the expense in most professional cases.

A quick word about VeriFactu

VeriFactu doesn’t change when you must invoice or what an invoice must contain. It focuses on how your invoicing software works: if you issue invoices (including simplified ones) using software, that software must generate a secure, traceable record for each invoice and prevent tampering. In other words, same invoicing rules, stricter software standards.

 A “ticket” is still a simplified invoice, and simplified invoices are also covered by VeriFactu if they are issued through software/TPV. So bars, shops, salons, and online stores that generate tickets digitally don’t need to start issuing full invoices to every customer — but their system needs to be VeriFactu-ready.

Let’s get started with the simplest case.

What to include on an invoice?

Much depends on the type of business that you run and who you issue it to. You might need to add “retention”, as explained below.

The actual design of the document is not relevant as long as its content is correct.

Generally speaking, an invoice should include the basic information below:

• The word “Factura” must be clearly visible.

“Factura” is the only document valid for tax purposes. Other documents such as “Pro-Forma”, “Delivery Note”, “Quote/Estimate” or tickets are not valid as full invoices.

• Your Tax ID (full name, CIF and address).

Here we mean the registered tax name of the business. For autónomos it is their personal name and NIE number. This is not the brand name your business may be known by, such as “Remote Studio” or “Nomad Fitness Coaching” or the name of your Shopify store / YouTube brand.

• The Tax ID of your client.

The same principle applies: use their official tax name and VAT number/NIF/NIE if applicable.

• Date and invoice number.

There must be consistency between date and number. I.e., invoice number 2 cannot be issued prior to invoice number 1. Besides that, there cannot be gaps in the series of numbers.

( A Verifactu- ready software simply with not allow to date an invoice with a date prior to the one of the lated invoice issued. ) 

• Price(s) of services/items provided (taxable amount), applicable IVA (generally 21%) and total.

If you sell items with different types of IVA, state separately the different taxable amounts and their applicable tax rates.

Example: General Invoice
(For simplicity the identification of company and client are not added. See points 2 and 3 above)

FACTURA
Company Tax ID      Client Tax ID
01/02/2025    num: 12

Our service………………….120.00
IVA. (21%)……………………25.20
Total…………………………..145.20

All the field mentioned above are predetermined with Quipu. We the auto-fill feature you will save a lot of time.

Related: What is VeriFactu and How Will It Affect Your Workflow in Quipu?

Let consider now some other cases:

When retention has to be added

In some instances the payer (your client) is obliged by law to withhold part of the money due and pay this to the tax office on your behalf. This is the case, among others, when an autónomo invoices a limited company.

The retention rates are:

• 7% in invoices issued by autónomos with less than two years of registration.

• 15% in the general case.

• 19% only for rental invoices (business premises / coworking spaces / sublet desks, etc.).

These percentages are calculated over the taxable base (price without IVA), not over the total.

Example: An autonomo invoices a SL company for some professional services provided.

In this case the invoice should look like this:

FACTURA
Company Tax ID      Client Tax ID
01/02/2025   num: 13

Our service……………….120.00
IVA. (21%)…………………25.20
Ret (15%)………………….-18.00
Total…………………………127.20

In Quipu there is a field to include the retention:

It is a good habit, when you have clients to whom you issue invoices with retentions, to ask them for a certificado de retenciones at the end of the year. This certifies that your client acknowledges having withheld money from you. You may need to show this when applying for a tax rebate.

When an autónomo invoices someone other than a limited company there is no obligation to include retentions.

Related: Deposits from clients given to pay others ( It discusses how to include them in the invoice)

Facturas rectificativas (Corrective invoices)

You cannot modify or delete an  invoice after it has been issued. 

• If you detect a mistake in the price, items, etc., you must produce a factura rectificativa.

• This invoice must refer to the one it corrects (number and date).

• It should list the item to cancel with a minus amount, and add the correct item/figure.

VeriFactu note

Corrective invoices are invoices too. If you issue them through software, they must be generated and recorded under VeriFactu just like any normal invoice.

Factura de abono (Credit invoice)

Sometimes you may need to cancel an invoice or refund money. To do this you issue a Credit Invoice:

• List the services/items with their price preceded by a minus.

• Refer clearly to the original invoice.

If issued through software, credit invoices are also VeriFactu-covered.

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Factura simplificada (Simplified invoices)

Sometimes, in shop-type businesses, it is valid to issue an invoice to “an unnamed client”. These are factura simplificada. Restaurants and shops use them, and they are properly declared as income. They include essentially all the above information except:

• the client’s details, and

• (depending on the case) the IVA breakdown.

These invoices are not valid for your client to offset the expense in most professional situations but they are necessary to declare your incomes. .

VeriFactu and simplified invoices

This matters for digital sellers too:

• If you sell B2C online (Shopify/WooCommerce/Etsy/Amazon), you don’t need to issue a full invoice with customer tax ID for every order.

• But each sale is still an invoice/simplified invoice in the background.

• If your platform or billing tool generates those documents, it must be VeriFactu-compatible.

So VeriFactu doesn’t change your customer flow — it changes the traceability of the invoices your system already creates.

You can make your invoices very simply and intuitively with Quipu, our invoicing and cash-flow platform — and we’ll keep you aligned with the upcoming VeriFactu requirements as they roll out.

Related: What expenses can you offset?