As of 2022, the IRS has new documentation requirements for startups and other companies filing amended tax returns that claim the research and development (R&D) tax credit. Because the IRS gets thousands of tax credit claims each year, they’re requiring taxpayers to provide much more documentation if their claims for the tax credit are considered deficient.What’s more, if the IRS rejects your claim, you’re barred from recovering tax credits or refunds, and you’re prevented from taking legal action. That’s why you should always work with a CPA with extensive experience in startup accounting.