Internet advertising entities facing legal uncertainty

International Tax Review is part of Legal Benchmarking Limited, 1-2 Paris Garden, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2026

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Internet advertising entities facing legal uncertainty

The internet advertising industry faces the greatest challenges of all searching for legal centainty when defining whether to collect the municipal tax on services (ISS) or the communication services tax defined by the states (ICMS) on the revenues arising from these services.



This is mainly due to the fact that taxpayers directly (if they are advertising services providers) or even indirectly connected to internet advertising (such as agents or intermediaries) have been dealing with both municipal authorities and state authorities defining that their activities are subject to their share of competence to tax.

Although controversy and disputes between ISS and ICMS are common, when dealing with information techlology there is always space for more controversy and new conflits of competence to take place. This is because, according to the legal certainty principle, taxation should be specifically defined, for each taxable event, and in many of the IT services, such as advertising, no legal provision has been that specific, giving room to a lot of interpretation by tax authorities.

The ISS is charged on the listed services described by law, among which there are a lot of definitions that could be strictly or remotely connected to internet advertising. The aforementioned list comprises from any intermediation, comission, agency or representation services to other related to advertising more as preparatory activities for advertising  such as data processing, software licensing, maintainance of internet pages, and graphic design composition for advertising etc. Those services are taxed in a range from 2% to 5% of the service depending on the municipality where the service provider is located.

Although the specific item of advertising as a vehicle is not listed, the municipality of São Paulo has repeatedly issued rulings in the last three months confirming that advertising and also internet advertising should be subject to ISS.

On the other hand, the state of São Paulo has issued tax assessments, in the past years, to relevant companies of the internet advertising market charging 25% ICMS, interest and penalties, considering that these companies (no matter their business model, or direct indirect connection to advertising) actually perform communication services without collecting ICMS.

Note that internet advertising has been around for a while, and to this respect neither federal constitution, nor these facts or ICMS legislation have changed since 1988 to justify the rise of those assessments. Thus, if everything remains the same, it seems that we are facing some new ideas from tax authorities, without the legal certainty that should precede them.

Internet advertising companies tend to take this controversy to Supreme Court. Some of them are already in judicial courts, some still in administrative level. All the judicial court cases have decisions or preliminary injuctions in favour of the taxpayer to avoid ICMS. Hopefully, legal certainty will prevail, and new ideas will be strictly connected to the new rules based on the due process of law.

Renata Correia Cubas is a partner focused on indirect taxation in Mattos Filho advogados.  

more across site & shared bottom lb ros

More from across our site

The US president’s threats expose how one superpower can subjugate other countries using tariffs as an economic weapon
The US president has softened his stance on tariffs over Greenland; in other news, a partner from Osborne Clarke has won a High Court appeal against the Solicitors Regulation Authority
Emmanuel Manda tells ITR about early morning boxing, working on Zambia’s only refinery, and what makes tax cool
Hany Elnaggar examines how AI is reshaping tax administration across the Gulf Cooperation Council, transforming the taxpayer experience from periodic reporting to continuous compliance
The APA resolution signals opportunities for multinationals and will pacify investor concerns, local experts told ITR
Businesses that adopt a proactive strategy and work closely with their advisers will be in the greatest position to transform HMRC’s relief scheme into real support for growth
The ATO and other authorities have been clamping down on companies that have failed to pay their tax
The flagship 2025 tax legislation has sprawling implications for multinationals, including changes to GILTI and foreign-derived intangible income. Barry Herzog of HSF Kramer assesses the impact
Hani Ashkar, after more than 12 years leading PwC in the region, is set to be replaced by Laura Hinton
With the three-year anniversary of the PwC tax scandal approaching, it’s time to take stock of how tax agent regulation looks today
Gift this article