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

Tax teams are responding to usual client demand in the region, albeit with increased working from home flexibility, local sources indicate
A 120-plus-day delay to refunds would cost taxpayers almost $3bn in additional interest, the Cato Institute warned; plus indirect tax updates from February
The Office for Budget Responsibility’s pessimistic pillar two forecast accompanied the UK chancellor’s muted Spring Statement, dubbed ‘as dull as possible’ by one adviser
Digital tax reform is dissolving the old ‘temporal buffer’, forcing systems, institutions, and professionals to adapt as real-time reporting reshapes governance, capability, and compliance
Our first instalment features analysis of Deloitte’s landmark EMEA merger, Donald Trump’s Supreme Court tariff showdown and Venezuela’s tax evolution
While some believe it could have a positive effect on the wider advisory landscape, others argue that HMRC’s ‘red tape’ exercise won’t deter bad actors
The political optics of the US’s carve-out deal are poor, but as the Fair Tax Foundation’s Paul Monaghan writes, it preserves pillar two’s guiding ethos
The big four firm reportedly sent ‘threatening’ correspondence to Unity Advisory over its hiring of ex-PwC partners; plus tax recruitment news from the week
Tom Goldstein, who was represented by US law firm Munger, Tolles & Olson, denied wilfully cheating on his taxes and blamed errors on his staff
Multinationals face rising TP scrutiny as global rules diverge. As Daniel Moalusi argues, strong, consistent documentation is now essential to minimise audit risk and protect tax positions
Gift this article