What documentation is required to claim the engineering r&d tax credit?

To claim the engineering r&d tax credit, firms must maintain detailed documentation, including project descriptions, technical reports, and records of research activities. Payroll records, employee timesheets, and financial statements showing qualified research expenses are essential. Supporting documents such as lab notes, design drawings, and prototypes help demonstrate eligibility. The IRS requires firms to prove that their work meets the Four-Part Test, making thorough documentation crucial for maximizing and defending an engineering r&d tax credit claim during audits.