The MIT License is everywhere. React, jQuery, Ruby on Rails, Bootstrap, Express.js — all MIT-licensed. For startups building commercial software, this is mostly good news. The MIT License permits commercial use, modification, and distribution with minimal restrictions. It does not require you to open-source your product. It does not restrict what you build on top of it.
But "minimal restrictions" is not the same as "no restrictions." MIT license compatibility with commercial software has nuances that matter in IP due diligence, enterprise contracts, and fundraising. This guide covers what the MIT License actually says, what it requires, and where the edge cases live — including for startups operating in Argentina and Brazil.
The MIT License is approved by both the Open Source Initiative (OSI) and the Free Software Foundation. It is the most commonly used open source license in the world, appearing in over 45% of packages in major package registries. For most commercial use cases, it is fully compatible.
What Is the MIT License?
The MIT License is a short, permissive software license originating from the Massachusetts Institute of Technology. The full text is fewer than 200 words. It grants broad permissions to anyone who receives the software, subject to one condition: the copyright notice and license text must be preserved in all copies or substantial portions of the software.
The license also contains a standard warranty disclaimer — the software is provided "as is," without warranty of any kind. This disclaimer is legally significant and appears in virtually identical form in most permissive open source licenses.
What the MIT License Permits for Commercial Use
The MIT License explicitly permits all of the following for commercial software development:
- Commercial use: You may use MIT-licensed software in commercial products and services, charge for those products, and retain all revenue.
- Modification: You may modify the source code freely, without any obligation to contribute modifications back to the original project.
- Distribution: You may distribute the software or your modified version of it, including as part of a proprietary product.
- Sublicensing: You may sublicense the software — for example, as part of a larger product you sell to customers.
- Private use: You may use the software internally without any disclosure or distribution obligations.
What the MIT License does NOT require: You are not required to open-source your product. You are not required to share modifications. You are not required to notify the original author. You are not required to mention the MIT-licensed component in your marketing materials (only in the software's copyright notice). This makes MIT one of the most startup-friendly licenses available.
The One Obligation That Trips Up Startups
The MIT License has one and only one user-facing obligation: preserve the copyright notice and license text "in all copies or substantial portions of the Software."
In practice, this means:
- In compiled/distributed software: include the MIT license text and copyright notice in the distribution (often in a NOTICES or LICENSE file, or in your app's About/Legal screen).
- In web applications: a legal notices page accessible from the application is standard practice.
- In SaaS products: attribution is typically handled through a software credits section in product documentation.
Failing to include attribution is, technically, a breach of the MIT License — and therefore copyright infringement. In practice, enforcement is rare for small-scale or inadvertent omissions. But in an IP due diligence review for fundraising or M&A, missing attribution for hundreds of MIT dependencies is a finding that will appear in the report. It is also the easiest compliance failure to fix.
MIT License Compatibility With Other Licenses
One of the MIT License's most important properties is its broad compatibility with other open source licenses. Understanding license compatibility is essential when your codebase mixes packages under different licenses.
| License | Compatible with MIT? | Notes |
|---|---|---|
| Apache 2.0 | Yes (one-way) | Apache 2.0 can incorporate MIT; the result is Apache 2.0 |
| BSD 2-Clause | Yes | Both permissive; fully compatible |
| BSD 3-Clause | Yes | Non-endorsement clause is compatible with MIT |
| GPL v2 | Yes (one-way) | MIT code can be used in GPL projects; result is GPL v2 |
| GPL v3 | Yes (one-way) | MIT can be incorporated into GPL v3; not vice versa |
| AGPL v3 | Yes (one-way) | Same as GPL v3 — MIT can flow into AGPL; not vice versa |
| LGPL v2/v3 | Yes | LGPL can use MIT components |
| Proprietary | Yes | MIT is explicitly compatible with proprietary/commercial use |
The critical insight from this table: MIT code can be incorporated into GPL or AGPL projects, but GPL/AGPL code cannot be incorporated into MIT projects without converting the combined work to GPL/AGPL. This is why a codebase that starts with all MIT dependencies is still at risk from a single GPL transitive dependency — the GPL's copyleft overrides the MIT's permissiveness when combining code.
Common MIT License Mistakes in Startup Codebases
Mistake 1: Missing Attribution Files
Most enterprise engineering teams do not maintain a comprehensive NOTICES file or license credits page. When hundreds of MIT-licensed packages are used, attribution is often entirely missing. This is technically non-compliant and appears as a finding in IP audits.
Mistake 2: Assuming MIT Means "No Legal Issues"
MIT permissiveness applies to the MIT-licensed component. It says nothing about the other licenses in your dependency tree. A codebase with 200 MIT packages and one AGPL package has a significant legal issue — not because of the MIT packages, but because of the one AGPL. Assuming "we use MIT and Apache" when there are unlisted transitive dependencies is a common source of IP audit surprises.
Mistake 3: Confusing MIT With Patent Rights
The MIT License grants copyright permissions. It does not grant patent rights. If a contributor to an MIT-licensed package holds patents that cover the functionality of that package, the MIT License does not protect you from patent infringement claims. The Apache License 2.0, by contrast, includes an explicit patent grant — which is one reason many enterprises prefer Apache 2.0 for commercially significant dependencies.
MIT License Compliance in Argentina, Brazil, and LATAM
In the LATAM startup ecosystem, MIT-licensed dependencies are ubiquitous — particularly in Node.js, Python, and React-based products developed by engineering teams in Buenos Aires, São Paulo, and Medellín. The MIT License's permissiveness means that compliance issues are generally minor.
However, two contexts make MIT compliance reviews important for LATAM-based startups:
Fundraising due diligence from US/EU investors: International investors conducting IP due diligence on LATAM startups apply the same standards as for US companies. A clean license audit — confirming that all MIT obligations are met and no GPL/AGPL contamination is present — is increasingly requested at Series A and above.
Enterprise customer onboarding in Brazil and Argentina: Large Brazilian and Argentine corporations (banks, energy companies, healthcare groups) have legal teams that review vendor software for open source compliance. A properly documented OSS compliance posture, including MIT attribution records, is part of a professional vendor package.
The WIPO and INPI Argentina both recognize software as a copyright-protected category of intellectual property, and open source licenses are treated as copyright licenses under both Argentine and Brazilian law.
Frequently Asked Questions
Can I use MIT-licensed code in my commercial SaaS product without open-sourcing it?
Yes. The MIT License explicitly permits commercial use and does not require you to open-source your product. You may use MIT-licensed components in a fully proprietary SaaS product, charge for that product, and keep your source code private. The only obligation is to include the MIT copyright notice and license text in the software — typically in a NOTICES file, license credits page, or About screen within the application.
What is the difference between the MIT License and Apache License 2.0 for a startup?
Both are permissive and commercial-friendly. The key difference is the patent grant: Apache 2.0 includes an explicit patent license from contributors, which the MIT License does not. For commercially significant dependencies — particularly infrastructure libraries where patent risk is a concern — Apache 2.0 is generally considered to provide stronger protection. For most npm and Python packages, the practical difference is minimal. A GitHub IP Audit maps all licenses in your dependency tree and flags any where the distinction matters.
Does using MIT-licensed code protect me from GPL contamination?
No. The MIT License governs what you are permitted to do with MIT-licensed code — it says nothing about other licenses in your dependency tree. If your codebase includes a GPL-licensed transitive dependency, the GPL's copyleft applies regardless of whether the direct dependency chain uses MIT licenses. This is why a full transitive dependency audit is necessary, not just a review of direct dependencies with permissive licenses.
How does IP due diligence treat MIT-licensed dependencies?
MIT-licensed dependencies are generally low-risk in IP due diligence. The standard checks are: (1) attribution requirements are met — copyright notices are included in distributions; (2) no mixed-license issues — the MIT code is not combined with GPL/AGPL in a way that triggers copyleft; and (3) patent analysis — for commercially critical MIT dependencies, whether any contributor patents are implicated. The LexMap GitHub IP Audit Starter ($149) covers all three for public repositories and delivers findings in 48 hours at a fixed price.
Verify Your MIT Compliance Before the Next Audit
The GitHub IP Audit Starter ($149) maps all licenses in your public codebase, confirms MIT attribution compliance, and flags any GPL/AGPL contamination hiding in the dependency tree. 48-hour delivery. Fixed price. IP due diligence–ready output.
Related Reading
Open Source Compliance Audit for LATAM Startups GPL Contamination Risks in Startup Code Apache License Patent Grants: Startup Risk GuideMIT License in the LATAM Legal Context
While the MIT License itself is a creature of US software practice, its legal implications play out differently across LATAM jurisdictions. In Argentina, Ley 11.723 (the Argentine Copyright Law) governs software protection, and the attribution requirements of the MIT License align well with the moral rights framework that Argentine law imposes on authors. However, the MIT License disclaimer of warranties may not fully align with Argentine consumer protection laws when software is distributed commercially.
In Brazil, the combination of Lei 9.610 (Brazilian Copyright Law) and the country strong software protection regime means that MIT-licensed code carries the same IP due diligence weight as proprietary software in M&A transactions. Investors conducting Series A due diligence increasingly request explicit license maps showing how MIT-licensed components are used, whether attribution is properly maintained, and whether any MIT components have been combined with copyleft-licensed code in ways that create license compatibility issues.
Our GitHub IP Audit Starter at $149 provides exactly this documentation with 48-hour delivery — a fixed price solution that gives your team and your investors confidence in your open source license compliance posture. Whether you are building in Argentina, Brazil, or expanding across Latin America, a clean license map is a prerequisite for professional fundraising. Get your report today and remove IP uncertainty from your path to growth.