A binding information (Processo 30252, despacho of 13 May 2026) published by the Autoridade Tributária e Aduaneira, Portugal’s tax authority, confirms that payment for a Software-as-a-Service subscription bought from a United States provider qualifies as business profit under Article 7 of the Portugal-United States double taxation convention, and is therefore not subject to Portuguese tax where the provider has no permanent establishment in Portugal. The case concerned a ChatGPT Plus subscription, but the reasoning reaches every Portuguese business that pays a US provider for access to a cloud platform. The treatment is favourable. The point that matters operationally is what the binding information attaches to it: the exemption from withholding is conditional on a procedure being completed in time, and a reporting declaration has to be filed, whether or not any tax is due. Not taxable in Portugal is not the same as nothing to do.
This note sets out what the binding information decides, why the characterisation of a digital payment is not automatic, the two obligations that remain even where the income is not taxable in Portugal, and the position for companies operating in Madeira.
What does the binding information decide?
The taxpayer asked a narrow question. A US provider invoices a Portuguese business for a SaaS subscription and has supplied a US tax residence certificate; is the Modelo 21-RFI form needed to avoid withholding, and does the Modelo 30 declaration still have to be filed?
The Autoridade Tributária began with the characterisation. SaaS is a model of software distribution, not a category of software: the software is not bought but subscribed to, normally over the internet, against a monthly or annual payment. There is no transfer of ownership and no licence to exploit the software; there is a right of access to the provider’s infrastructure, with support and maintenance. On those facts, the income is the business profit of the provider under Article 7 of the Portugal-United States convention, because the customer only accesses the platform remotely and no software property changes hands.
Under Article 7, the profit of a US enterprise is taxable only in the United States, unless the enterprise operates in Portugal through a permanent establishment and the profit is attributable to it. The US provider in the case had no permanent establishment in Portugal, so the payment is not subject to tax in Portugal. The binding information binds the Autoridade Tributária in relation to the taxpayer who requested it and the facts it describes; it is not a general regulation, but it is a clear statement of the AT’s position that a business in the same situation can read as guidance.
Why the characterisation is not automatic
The favourable result follows from the characterisation, and the characterisation is the part that is easy to get wrong. The same payment to the same provider can fall under a different article of the convention.
If the arrangement is a software licence rather than a service (a right to use copyright-protected software, a download and local installation under licence, or a transfer of exploitation rights), the income can qualify as royalties under Article 13 of the Portugal-United States convention, with a different allocation of taxing rights. The binding information reached business profit, and not royalties, only because the ChatGPT Plus subscription was, on the provider’s own description, pure platform access: no download, no exploitation licence, no control over the software.
Portugal also reads the royalties article more broadly than the OECD mainstream. Together with Spain and Mexico, Portugal entered an observation to the Commentary on Article 12 of the OECD Model Convention, recorded at paragraph 28, declining to follow several paragraphs of the standard interpretation. Portugal’s position is that software payments fall under the royalties article, where only part of the software rights are transferred, and also where the software is acquired for use in a business and is not entirely standardised but adapted in some way to the acquirer. The practical consequence is that the box a digital payment falls into is narrower for business profit, and wider for royalties, than a reading of the OECD Commentary alone would suggest. A SaaS subscription, a licensed download, and a customised enterprise deployment are three different treatments, and the contract and the provider’s description are what decide which one applies.
The two obligations that remain
Even where the conclusion is that the income is not taxable in Portugal, two obligations follow, and the binding information addresses both.
The first is the Modelo 21-RFI. The exemption from withholding tax is not automatic. To be relieved of the obligation to withhold, the paying entity has to hold proof that the treaty conditions are met: the Modelo 21-RFI form, completed by the beneficial owner of the income, accompanied by a document issued by the US tax authorities attesting the provider’s tax residence and its subjection to income tax in the United States. Article 98 of the CIRC requires that proof be in hand by the end of the deadline for delivering the tax that would otherwise have had to be withheld. If the form and the certificate are not obtained in time, the relief is not available for that payment, and the paying entity is exposed for the tax it did not withhold.
The second is the Modelo 30. This applies regardless of whether any tax is due. Under Article 128 of the CIRC (Corporate Income Tax Code), read with Article 119(7)(a) of the CIRS (Personal Income Tax Code), a Portuguese entity paying income to a non-resident must file an official declaration with the Autoridade Tributária by the end of the second month following the payment. That declaration is the Modelo 30, approved by Portaria n.º 372/2013, of 27 December, with filling instructions approved by Portaria n.º 332-A/2015, of 5 October. The reporting obligation is not switched off by the treaty: the income is reported on the Modelo 30 even though, under Article 7, it is not taxed in Portugal.
The position for companies operating in Madeira
A company licensed in the Madeira International Business Centre is a Portuguese resident taxpayer and, when it pays a non-resident provider, a paying entity for withholding purposes. The reduced IRC rate that the MIBC regime confers does not change that role. An MIBC company, like any other Portuguese company, that subscribes to a US SaaS provider has to assess the characterisation of the payment, obtain the Modelo 21-RFI and the residence certificate if it wants to be relieved of withholding, and file the Modelo 30 within the deadline.
For businesses in Madeira the practical exposure is volume. Cloud subscriptions, AI tools, hosting, and software platforms bought from US and other non-resident providers are now a routine line of expenditure, and each recurring payment carries the same procedural obligations as a one-off. A business that has not built the Modelo 21-RFI collection and the Modelo 30 filing into its payments process is accumulating exposure quietly, one subscription at a time.
Where MCS can assist
MCS advises on the characterisation of payments to non-resident service and software providers under Portugal’s double taxation conventions, including the distinction between business profit and royalties and the effect of Portugal’s observation to the OECD Commentary. We advise on the Modelo 21-RFI procedure and the documentation required to support relief from withholding, on the Modelo 30 reporting obligation, and on building both into a recurring-payments compliance process for companies with a high volume of foreign subscriptions, including MIBC-licensed entities.
The procedural next step for any business uncertain about its position is a review of its payments to non-resident providers, the characterisation of each, and the documentation held against the Modelo 21-RFI and Modelo 30 requirements. Engagements are quoted based on that review.
Contact MCS for a scoping discussion.
This article is provided for general information purposes only and does not constitute legal, tax, financial, or migration advice. The content reflects the legal and regulatory framework in force at the date of publication; subsequent amendments to the relevant statutes, regulations, administrative orientations, or jurisprudence may render parts of the content inapplicable. At the date of preparation of this article, the description set out above reflects the binding information issued by the Autoridade Tributária e Aduaneira in Processo 30252 (despacho of 13 May 2026) and the legal provisions there cited; that binding information binds the Autoridade Tributária only in relation to the taxpayer who requested it and the specific facts it describes, and the case references, the articles of the Portugal-United States double taxation convention, the provisions of the CIRC and the CIRS (Personal Income Tax Code), and the Portarias identified above should be verified against their published texts before any decision is taken. The characterisation of a digital or software payment depends on the specific contractual arrangement, and a different arrangement may produce a different treatment. No professional or client relationship is created by the reading of this article, and readers should not act, or refrain from acting, in reliance on the content without obtaining advice tailored to the specific facts of their situation. Madeira Corporate Services accepts no liability for any decision taken on the basis of this article in the absence of a formal engagement.
Miguel Pinto-Correia holds a Master Degree in International Economics and European Studies from ISEG – Lisbon School of Economics & Management and a Bachelor Degree in Economics from Nova School of Business and Economics. He is a permanent member of the Order of the Economists (Ordem dos Economistas)… Read more
