We present the main requirements that an invoicing program must meet from the user's perspective, combining legal requirements with the most important functional and operational aspects in business management. Legal requirements and impositions of the Tax Authority[[HMLTAG7]][[HMLTAG8]]1.1. Use an invoicing program certified by the Tax Authority[[HMLTAG10]]For most companies and businesses, it is mandatory to use an invoice program certified by the Tax and Customs Authority (AT). The user must confirm that the software he intends to use is on the official list of certified programs and always use the duly certified version.
In practice, this means that the program must:
- [[HMLTAG15]][[HMLTAG16]]Consist on the public list of programs certified by the AT: tax.
1.2. Ensure the issuance of invoices with all mandatory elements
The invoicing program must allow issuing invoices that include all mandatory elements provided for in legislation, such as:
Date of issuance;
Sequential number of the invoice, within a defined series;
- [[HMLTAG44]]Name or corporate name and NIF of the supplier of goods or service provider services;
Name or corporate name and NIF of the customer (when applicable);
- [[HMLTAG52]]Description of the goods or services, indicating quantities;
Unit prices and total value;
- [[HMLTAG60]]Applicable VAT rates and respective amount of tax;
Specific mandatory mentions (special regimes, exemptions, reverse charge, etc., when applicable).
[[HMLTAG66]][[HMLTAG67]][[HMLTAG68]]The user must be able to fill in these fields in a simple and coherent way, and the program must ensure that the numbering of invoices is continuous and flawless within each series.1.3. ATCUD and QR code on fiscally relevant documents
Certified invoicing programs are required to print, on fiscally relevant documents, the unique document code (ATCUD) and, when applicable, the QR code. The user must ensure that the program:
- [[HMLTAG78]]Allows you to communicate billing series to AT to obtain the series validation code; validated;
Prints the QR code on documents required by current legislation. Generation of the SAF-T (PT) file
Taxable persons who use certified invoicing programs are required to be able to export the SAF-T (PT) file, which is used to communicate elements to the Tax Authority. The program must allow the user to:
Generate the SAF-T (PT) file for the desired period;
Save or download the file in a compatible format with submission on the Finance Portal;
[[HMLTAG104]]Correct any data errors before final generation, when identified by the accountant.
1.5. Integrity, unalterability and registration of operations
[[HMLTAG9]]From a legal point of view, the invoicing program must guarantee that the documents issued cannot be altered without leaving a trace. For the user, this translates into requirements such as:Impossible to delete invoices already issued;
Corrections made through specific documents (for example, notes credit);
Registration of usage logs (who issued, when, what document);
[[HMLTAG24]][[HMLTAG25]]Correct automatic calculations of values, taxes and totals.
2. Functional and operational requirements of the program (not directly imposed by AT)
2.1. Types of documents that the program must issue
[[HMLTAG37]]A complete invoicing program must allow the user to issue, at least less:Invoice;
[[H TMLTAG44]]
Invoice-receipt;
Invoice simplified (if applicable); payment;
Other documents to support invoicing (proposals, quotes, guides, etc.), when relevant to the business.
[[HMLTAG63]][[HMLTAG64]][[HMLTAG65]]The user must be able to easily choose the type of document appropriate to each situation, without the need for advanced tax knowledge.2.2. Management of customers, items, prices and taxes
In practice, the invoicing program is also a management tool. Therefore, it must allow:
Creation and maintenance of customer files (billing data, contacts, NIF, foreign taxpayer status, etc.);
Creation of product articles and services, with description, units, base prices and associated VAT rates;
Automatic application of the correct VAT rates, in accordance with legislation;
Management of discounts, promotions and commercial conditions specific per customer or item;
Configuration of different billing series by type of document or area of business.
2.3. Reports and information consultation
From the user's point of view, it is essential that the program facilitates business control. Some essential reports and queries include:
List of invoices issued by period, customer or series;
Summary of sales by VAT rate and by type of document;
Invoicing maps to support accounting;
[[HMLTAG114]][[HMLTAG115]]Quick consultation of each customer's situation (open invoices, purchase history, etc.);
Export data in common formats (e.g. file to Excel or CSV).
3. Operational and technological requirements
3.1. Type of solution: local or in the cloud
The user must evaluate the technological model that best adapts to the business:
Program installed on a server or local computer: can give more control over the infrastructure, but requires backup, updates and security care;
[[HMLTAG9]]Cloud billing program (SaaS): accessible via the internet, allows working from various devices and locations, with technical maintenance and updates being the responsibility of the supplier.
In any case, it is essential to check whether the software guarantees adequate availability, acceptable response time and compatibility with the equipment and operating system used.
3.2. Multi-user and permissions management
In companies with more than one employee issuing or consulting invoices, it is important that the program allows:
- [[HMLTAG24]]Create multiple users with credentials own;
Define profiles and permissions (who can invoice, who can just consult, who can configure the system, etc.);
[[HMLTAG30]][[HMLTAG31]]Record the actions carried out by each user.
3.3. Security, backups and data protection
The billing program handles sensitive customer data and relevant tax information. From the user's point of view, it must ensure:
Secure communications (e.g. encrypted connection when used via browser);
[[HMLTAG46]][[HMLTAG47]][[HMLTAG48]]Regular backups that are easy to recover in case of failure or loss of data;Robust authentication mechanisms (strong passwords, two-factor authentication where available);
Compliance with the General Data Protection Regulation (GDPR) in the processing and storage of personal data.
3.4. Integrations with other systems
For many businesses, it is a relevant advantage that the invoicing program integrates with other systems, such as:
- [[HMLTAG68]]Accounting software, for automatic sending of data to the accountant;
Online stores and e-commerce platforms;
Point of sale systems (POS) information.
4. Customer support and service requirements
[[HMLTAG90]]4.1. Technical support and monitoring[[HMLTAG92]]A good invoicing program is not just about the software. It is essential that the user has:- [[HMLTAG95]][[HMLTAG96]]Accessible support channels (email, telephone, chat) in Portuguese;[[HMLTAG98]][[HMLTAG99]][[HMLTAG100]]Response times suited to the needs of the user business;
Support at critical moments, such as the start of activity, legal changes or problems technical.
4.2. Documentation, training and learning resources
Ideally, the program should provide:
Simple and user-friendly guides updated;
Video tutorials or step-by-step articles for the most common operations;
Clear information about news, legal changes and new features.
5. Commercial and contractual requirements
5.1. License and cost model
Before subscribing to a billing program, the user must carefully analyze:
- [[HMLTAG8]]Whether the model is a one-time purchase, monthly/annual subscription or hybrid;
Whether there are extra costs per company, per user, per volume of documents or for certain functionalities;
Whether legal and technical updates are included in the price;
Whether there are minimum loyalty periods.
5.2. Output conditions and data portability
Another important aspect is knowing what happens if, in the future, the user wants to change programs. It is recommended to ensure that:
Data can be exported in an open format (e.g. SAF-T, CSV or similar);
[[HMLTAG34]][[HMLTAG35]][[HMLTAG36]]Access to historical data is ensured for a period reasonable;There are clear procedures for terminating the contract and for providing backup copies.
6. Practical checklist: legal requirements vs functional requirements
When choosing or reviewing your invoicing program, the user can use the following simplified checklist, clearly separating what is imposed by the Tax Authority and what is required of the software itself to function well on a day-to-day basis. day:
Checklist of legal requirements and AT impositions:
The program is certified by the Authority Tax?
Does it include all mandatory elements on the invoice (date, sequential numbering, NIF, description, VAT, etc.)?
Generates and prints the ATCUD correctly and the QR code, where required? the integrity and inalterability of the data?
Checklist of functional and operational requirements of the program (not directly imposed by AT):
Does it allow me to issue all the types of documents I need (invoice, receipt invoice, credit notes, etc.)? enough for me to monitor invoicing and support accounting?
Does it work in a stable, fast and secure way, with regular backups?
[[HMLTAG96]][[HMLTAG97]][[HMLTAG98]]Integrates with the systems I use (accounting, e-commerce, POS, payment methods)?Does it provide good technical support, documentation and timely legal updates?
- [[HMLTAG106]]The pricing model is clear and appropriate to the size of my business?
Can I export and recover my data if, one day, I want to change software?
From the user's point of view, an invoicing program is not just a tool for issuing invoices: it is a central component of business management and compliance with tax obligations. Ensuring that the software is certified, complies with all legal rules and, at the same time, offers good features, security, support and transparent commercial conditions is essential to work with confidence and reduce risks before the Tax Authority. business and avoid future problems.