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Technical vulnerability and consumer law
Technical asymmetry between the client and the vendor may justify the application of Brazilian consumer law and reversal of the burden of proof.
ERP Radar · TJSP & Technology
TJSP &
Technology
Second Four-Month Period 2026 (May–August)
Selected São Paulo Court of Appeals (TJSP) decisions issued between May and August 18, 2026 concerning the implementation, licensing and operation of enterprise software. The summary below sets out the main takeaways, followed by our analysis of the selected decisions.
Advocacia Adriano Dib · São Paulo, August 2026
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44.5% completed may not be enough
Percentage of completion is no substitute for utility: the key question is whether the delivered system could actually be used.
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No Go-Live does not necessarily mean zero compensation
In the event of early termination, services demonstrably performed may still be compensated, including under Article 603 of the Brazilian Civil Code.
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Implementation must be proven
Billed hours and commercial documents do not, by themselves, prove installation, configuration, training and readiness for use.
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No Go-Live: documentary evidence may suffice
The TJSP upheld summary judgment and stated that the outcome would have been the same even without applying consumer law.
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Minor defects do not necessarily amount to breach
Remediable defects that do not prevent use of the system do not, by themselves, justify abandoning the project.
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Isolated failures ≠ unusability
To terminate the contract, proving bugs is not enough: their severity or frequency must be shown to have rendered the system unfit for use.
Common thread. The decisions suggest a functional approach to technology contracts: who was responsible for leading the project, what was actually delivered, whether Go-Live occurred and, after Go-Live, whether the defects impaired the system’s utility.
Analysis of the selected decisions
1. Technical vulnerability and consumer law
Facts
An agricultural company contracted for the licensing and implementation of management software. After the project failed, the vendor filed a collection action; the client alleged failures in modules and integrations and requested evidentiary proceedings.
Decision
The TJSP vacated the judgment entered without evidentiary proceedings. It found that the client was technically vulnerable vis-à-vis the specialized vendor, applied the mitigated final-consumer doctrine, reversed the burden of proof and ordered expert and oral evidence.
Why it matters
The decision shows that a project’s technical complexity may directly affect the evidentiary framework. The client’s size, standing alone, does not rule out technical vulnerability.
2. 44.5% completed may not be enough
Facts
Technical evidence quantified the services performed at 44.5%. Despite that progress, the system had not reached a stage at which the client could actually use it.
Decision
The TJSP upheld the vendor’s liability and rejected contributory fault. It emphasized the vendor’s superior technical command of the subject matter and its duty to ensure the software project was properly developed.
Why it matters
The decision reinforces a central point in implementation disputes: effort or percentage of completion does not, by itself, amount to a useful result. The vendor’s specialized expertise also matters when assessing responsibility for project management.
3. No Go-Live does not necessarily mean zero compensation
Facts
The client terminated an implementation agreement early. The agreement provided for payment for services performed, and the expert evidence estimated that approximately half of the work had been completed.
Decision
The TJSP held that the vendor was entitled to overdue installments and compensation corresponding to 50% of the services contemplated through the end of the contract, relying on the contractual provision, expert evidence and Article 603 of the Brazilian Civil Code.
Why it matters
This is a relevant decision for vendors: the absence of Go-Live does not necessarily eliminate the economic value of work already performed. Appropriate contractual drafting and objective evidence of progress may be decisive.
4. Implementation must be proven
Facts
The vendors sought payment and a contractual penalty following termination of an implementation agreement. They alleged approximately 80% completion, but waived expert evidence and submitted documents that did not concretely establish installation, configuration or training.
Decision
The TJSP upheld dismissal of the claim. It found that the agreement, proposal, invoices, emails and notice were insufficient to prove the actual progress of implementation.
Why it matters
The case distinguishes effort from delivery. To recover for work performed, a vendor should build contemporaneous, technically verifiable evidence of the stages actually completed.
5. No Go-Live: documentary evidence may suffice
Facts
The client paid monthly fees, but the ERP system never went into production. The vendor alleged contributory fault and argued that the lack of expert evidence impaired its right to a defense.
Decision
The TJSP upheld full restitution and judgment without expert evidence. It applied consumer law, but stated that the outcome would have been the same even without it because the documentary evidence established the breach. Contributory fault was rejected for lack of concrete evidence.
Why it matters
The decision reduces the practical importance of an abstract debate over consumer law when documentary evidence is robust. It also shows that expert evidence is not automatic and that contributory fault requires specific proof of the client’s causal contribution.
6. Minor defects do not necessarily amount to breach
Facts
The client resisted contractual performance on the ground that the platform was defective. Expert evidence concluded that the system was ready for use and had only minor non-conformities that could be corrected in approximately one week.
Decision
The TJSP rejected the defense of non-performance. It held that minor defects may occur and should be corrected, provided they do not prevent the solution from being used in production.
Why it matters
The decision establishes an important threshold for implemented systems: remediable defects do not amount to material breach. The focus should be on the functional impact of the defect.
7. Isolated failures ≠ unusability
Facts
Two companies sought termination and damages based on recurring failures in management software. They identified sixteen incidents of varying severity but continued to use the system for a significant period.
Decision
The TJSP acknowledged the existence of failures but distinguished bugs and isolated outages from a system that was unusable or unfit for purpose. Without technical evidence showing that the number and severity of the problems exceeded an acceptable level, it found no breach. Continued use of the system also weighed against the clients.
Why it matters
The decision articulates a clear rule for the operational phase: software need not be perfect, but it must be functional. To turn bugs into a contractual breach, a party must demonstrate a material impact on the system’s utility.