The invoicing regulation sets out how you must document every sale at the point of sale. Many merchants still use the word "receipt" informally, but it's worth being clear about which documents have fiscal validity and how they're treated under the current rules.
This article explains the difference between a receipt and an invoice (in its different forms), and how Comply handles it automatically so your business always stays compliant.
Note: Shopify still adds a receipt number to every invoice printed at the point of sale (Shopify POS). That number is only an internal reference: it has no fiscal or legal effect.
What was a traditional receipt?
Traditionally, a "receipt" was a non-fiscal document with limited validity:
It was handed over for sales to individuals, without identifying the customer.
It didn't let the customer deduct VAT.
It wasn't considered a legal invoice.
It was handy in physical stores for small purchases, but it didn't meet the requirements of a fiscally valid invoice.
What does the current invoicing regulation require?
Under the invoicing regulation, you can't issue a "plain receipt with no fiscal validity." Every sale, however small, must be documented with an invoice, which can be simplified or complete. Each one has a minimum required content.
This isn't new: the invoicing regulation (Royal Decree 1619/2012) replaced the old receipts with the simplified invoice, and it applies throughout Spain.
The simplified invoice (what we used to call a receipt)
This is the most common document at the point of sale. At a minimum, it must include:
A number and series, with sequential numbering.
The issue date (and the date of the sale, if different).
The issuer's NIF and name.
A description of the goods or services.
The VAT rate applied (or the note "VAT included") and the total amount.
The complete invoice
When the customer is identified or asks for one, you issue a complete invoice, which adds the following:
The customer's details: name, NIF, and address.
The tax base and the VAT amount, shown separately.
Note: A simplified invoice only lets the customer deduct VAT if it also includes the customer's NIF and address and the VAT amount shown separately. If your customer needs to deduct VAT, issue a complete invoice.
What's the difference between a receipt and an invoice?
Concept | Does it still exist today? | Fiscally valid? | Does Comply issue it? |
Receipt (no fiscal validity) | ❌ No | ❌ No | ❌ |
Simplified invoice (FS) | ✅ Yes | ✅ Yes | ✅ Automatically |
Complete invoice (FC) | ✅ Yes | ✅ Yes | ✅ When the customer is identified |
Corrective invoice (RS or RC) | ✅ Yes | ✅ Yes | ✅ Automatically |
What does Comply generate in each case?
Depending on how you process the sale in Shopify POS or the Shopify admin, Comply automatically generates the right document:
Scenario | Document Generated by Comply |
Sale without identified customer | Simplified Invoice (FS) |
Sale with identified customer (e.g. NIF, business name) | Full Invoice (FC) |
Return or exchange of a simplified invoice | Simplified Rectified Invoice (RS) |
Return or exchange of a full invoice | Full Rectified Invoice (RC) |
Comply automatically generates the right document, with the sequential numbering and all the required content the invoicing regulation calls for, so you don't have to do anything else.