The future of invoicing fits inside a QR Code

A business requires you to always stay on top of tax obligations. The implementation of QR Codes on invoicing documents and other fiscally relevant documents is not just a formality; it is a legal requirement from the Tax Authority (AT) aimed at simplifying taxpayers’ lives and fighting tax evasion. If you run a business in Portugal, understanding how this two-dimensional code works is crucial to ensuring your invoicing complies with Decree-Law no. 28/2019. With Moloni ON, this process is fully automatic, but it is important to understand what is behind this technology in order to optimize your business management.

Key conclusions

• Legal obligation: The QR Code has been mandatory on all invoices and fiscally relevant documents since January 2022.
• TA certification: Only software certified by the Tax Authority, such as Moloni ON, can generate valid and compliant codes.
• Data communication: The code contains essential invoice data (tax number, amounts, VAT), allowing the end consumer to report expenses without providing a tax number at the time of purchase.
• Readability: The code must be printed with sufficient quality to be scanned by mobile devices and official apps such as “fatura@t”.
• Location: It must appear on the first or last page of the sales document.

What is the QR Code on invoices and what is it for?

The QR Code (Quick Response Code) is a two-dimensional barcode that stores key information about a commercial transaction. In Portugal, its implementation was designed to increase transparency and facilitate interaction between the consumer, the merchant, and the Tax Authority.

When you issue an invoice in Moloni ON, the software automatically generates this code according to AT technical specifications. For you as a business owner, it ensures legal compliance. For your client, it is a fiscal citizenship tool: they can scan the invoice with their smartphone and register it in e-Fatura, even if they forgot to request their tax number at the time of payment.

Who is required to use the QR Code on documents?

If you run a business in Portugal and issue invoices, the short answer is: you. The requirement applies to all VAT taxpayers with a registered office, permanent establishment, or tax residence in Portugal who use certified invoicing software.

This includes not only standard invoices but also simplified invoices, invoice-receipts, and credit notes. Even if you are a freelancer or small retailer, as long as you use software such as Moloni ON, including this element is mandatory for the document to be considered legally valid in case of inspection.

What are the technical requirements for printing the QR Code?

The Tax Authority leaves no room for improvisation. There are strict rules regarding how the QR Code must appear on your documents. The code must have a minimum size of 3x3 cm (or larger, depending on data density) to ensure it can be scanned by any smartphone camera without difficulty.

In Moloni ON, all technical aspects are handled automatically. The software calculates the document hash and concatenates all mandatory fields—such as your tax number, client tax number, date, net amount, VAT rates, and total amount—turning them into the image printed on paper or PDF. The golden rule is: the QR Code must be visible and cannot be covered by other graphical elements.

How to implement the QR Code with Moloni ON?

The good news is that if you already use Moloni ON, you do not need to hire a developer or perform complex configurations. The system is designed to be plug and play when it comes to tax compliance. Once you create your account and configure your print templates, the code is automatically inserted into standard layouts.

You only need to choose the template that best fits your brand identity. Moloni ON ensures that whether you send the invoice by email or print it on a thermal printer, the QR Code maintains data integrity and complies with Order 195/2020. It is the simplest way to sleep peacefully knowing your business is 100% compliant.

Where should the QR Code be placed on the document?

According to AT guidelines, the QR Code must appear on the document body, preferably after the product or service details. If your invoice has multiple pages, it must appear on the first or last page.

It is important not to hide or reduce the code excessively to save space. In Moloni ON, print layouts already follow best design and compliance practices, placing the code in a clearly visible position so customers can easily scan it if needed.

What are the benefits of the QR Code for your business management?

Although it may seem like just another state-imposed requirement, the QR Code brings indirect benefits to your operation. The main one is reducing invoice communication errors. Since the code contains all structured information, the risk of discrepancies between what you declare and what the customer communicates is minimised.

Additionally, using modern software such as Moloni ON, which natively generates these elements, conveys an image of professionalism and technological modernity to your customers. In today’s market, being aligned with the Tax Authority is a seal of trust that separates amateur businesses from solid companies prepared for the digital future.

Difference between QR Code and ATCUD: Do you need both?

This is a common question. Yes, you need both. While the QR Code is the visual element containing transaction data, the ATCUD (Unique Document Code) is an alphanumeric code that must appear immediately above or next to the QR Code.

The ATCUD is used to uniquely identify an invoice, regardless of issuer or year. In Moloni ON, both elements are generated simultaneously. When you communicate your invoicing series to the AT and obtain the validation code, the software merges this information to create the ATCUD and the final QR Code. Without one, the other loses fiscal validity, which is why it is essential to use a platform that automates this data matching process without manual intervention.

How to verify if your QR Code is valid?

If you want to be sure everything is working as it should, you can do a simple test. Take your smartphone, open the camera or a QR Code reader app, and point it at an invoice issued by Moloni ON. You should see a long text string beginning with something like “A:XXXXXXXXX” (where X is your Tax ID).

If the data displayed on your screen matches the invoice values, your system is working perfectly. The AT also provides the “fatura@t” app, which is the ultimate test: if the app recognises the document and allows its registration, your invoicing process is flawless.

The impact of not including the QR Code: Fines and Penalties

Do not ignore this rule. Issuing documents without a QR Code or with an unreadable code is considered a serious tax offence. Fines for companies can be substantial, varying according to turnover size and severity of non-compliance.

In addition to the financial cost of fines, you risk having your accounting subjected to stricter scrutiny by the AT. By using Moloni ON, you eliminate this risk at the source. The software prevents the issuance of documents that do not meet minimum certification requirements, acting as a safety net for your financial management.

Simplify your life with the right technology

The implementation of QR Codes reflects the digitalisation of the Portuguese economy. Although it adds a layer of technical requirements, tools such as Moloni ON transform this complexity into something invisible and automatic for the end user.

Focusing on what really matters—growing your business—is only possible when you have the confidence that your invoicing is handled by specialists. If you still have doubts about adapting your documents, or if your current software does not provide the guarantees you need, switching to a cloud-based, certified solution designed for the Portuguese market is the next logical step for your company.