R&D Ledger is not affiliated with or endorsed by MainStreet (mainstreet.ai). This independent comparison is based on publicly available information and is provided for educational purposes.
Last competitor information verified: August 2026
Note: MainStreet Tax Credits is now mainstreet.ai. The original mainstreet.com domain now operates as a separate holding-company business. R&D tax credit services are currently offered at mainstreet.ai. This page uses the current official brand and URL.
Businesses evaluating startup-focused R&D tax credit options may encounter MainStreet (mainstreet.ai). This page provides an independent comparison of MainStreet’s publicly described model and the year-round internal documentation approach represented by R&D Ledger. For a broader framework, see our page on how to choose an R&D tax credit provider.
What MainStreet Publicly Offers
According to mainstreet.ai’s current website, MainStreet provides R&D tax credit software with subject matter experts who identify and claim tax credits and business incentives. The website describes a process where the business answers questions about its team and what it builds, MainStreet calculates the credit, the business’s CPA files it, and the business receives cash back.
MainStreet’s website describes IRS-ready Form 6765 documentation, Section G compliance, up to $1M in audit protection, and multiple pricing options. The website states that MainStreet’s success-based pricing starts at 15%, compared to typical firms that take 20–30%, and describes flat-fee, pay-in-full, and monthly payment plan options.
MainStreet’s website describes industries including software/SaaS/AI, manufacturing, life sciences/biotech, food/beverage/agriculture, construction/AEC, logistics/transport, energy/cleantech, fintech/insurtech, electronics/semiconductors, and aerospace/defense.
Provider and Engagement Model
MainStreet describes itself as a software-plus-service provider for startups. According to its website, the model involves the business answering questions, MainStreet calculating the credit, and the business’s CPA filing it. The pricing model is success-based, starting at 15%, with flat-fee and payment-plan options.
This is a software-plus-service model oriented toward startups: MainStreet calculates the credit and provides documentation, and the business’s own CPA files it.
How the Process Appears to Work
According to mainstreet.ai’s website, the process involves answering questions about the team and what it builds, MainStreet sizing the federal and state credits, and the CPA filing IRS-ready Form 6765 documentation. The website describes the process as taking as little as three minutes to sign up and integrate with a payroll system.
Documentation Approach
MainStreet’s documentation approach, as described on its website, involves MainStreet producing IRS-ready Form 6765 documentation that is Section G compliant. The website states that the documentation is handed off to the business’s CPA for filing.
Role of Software
Software is part of MainStreet’s model. According to its website, the platform integrates with payroll systems and sizes credits. The software is paired with subject matter experts rather than operating fully standalone.
Role of Human Professionals
Human professionals are part of MainStreet’s model. According to its website, MainStreet provides subject matter experts who identify and claim credits. However, the filing is done by the business’s own CPA, not by MainStreet.
Year-Round vs. Study Considerations
MainStreet describes a process where the business answers questions and MainStreet calculates the credit. This appears oriented toward a claim cycle rather than continuous year-round documentation by the internal team. Year-round internal documentation, as represented by R&D Ledger, involves the business’s own team organizing project, technical, cost, and evidence records throughout the year for professional review. For more on this distinction, see our page on year-round R&D documentation vs. annual study.
What a Buyer Should Compare
A buyer evaluating MainStreet against year-round internal documentation software may consider:
- Software-plus-service vs. documentation-first: MainStreet combines software with subject matter experts. Does the buyer want a provider that calculates the credit, or does it want to organize records internally?
- Startup pricing: MainStreet describes success-based pricing starting at 15%. How does this compare to other options?
- CPA filing: MainStreet provides documentation for the buyer’s CPA to file. Does the buyer have a CPA ready to file?
- Audit protection: MainStreet describes up to $1M in audit protection. Does the buyer value this?
- Industry coverage: MainStreet describes multiple industries. Does the buyer’s industry align?
For a broader comparison, see our page on R&D tax credit software pricing.
When MainStreet’s Model May Make Sense
MainStreet’s model may make sense for a business that:
- is a startup wanting a provider to calculate the credit with subject matter experts;
- wants success-based pricing starting at a lower percentage;
- has a CPA who will file the credit using MainStreet’s documentation;
- values audit protection; and
- operates in an industry MainStreet serves.
When Year-Round Internal R&D Tracking May Make Sense
Year-round internal R&D documentation may make sense for a business that:
- wants to organize project, technical, cost, and evidence records throughout the year internally;
- already has a CPA who handles filing and needs organized records to support that work;
- prefers continuous documentation rather than a claim-cycle engagement; and
- wants a documentation workspace that captures projects, experimentation, costs, and evidence as they occur.
For more, see our page on best R&D tax credit software.
Can the Two Approaches Coexist?
A business could maintain year-round project and evidence records in a documentation workspace and also use a provider like MainStreet for the credit calculation. The internal records could supply organized project, cost, and evidence data to support MainStreet’s calculation. The two approaches are not mutually exclusive: a business might use internal documentation for ongoing recordkeeping and a provider for the credit calculation and documentation generation.
Questions to Ask Before Choosing
- Does the business want a provider to calculate the credit, or does it want to organize records for its own CPA?
- How does the success-based pricing starting at 15% compare to other options?
- Does the business have a CPA who will file the credit?
- How important is audit protection, and what are its terms?
- Does the business’s industry align with the provider’s coverage?
Key Takeaway
MainStreet (mainstreet.ai) is a software-plus-service provider for startups that calculates R&D tax credits with subject matter experts, provides IRS-ready Form 6765 documentation for the business’s CPA to file, and offers success-based pricing starting at 15%. Year-round internal R&D documentation, as represented by R&D Ledger, involves the business’s own team organizing project, technical, cost, and evidence records throughout the year for professional review. The two approaches differ in who calculates the credit and how records are maintained, and a buyer’s choice depends on its preference for provider involvement and internal documentation. For more on choosing a provider, see our page on how to choose an R&D tax credit provider.