Describing business benefits instead of technological advancement
CRA looks for technological obstacles and the systematic work to overcome them. Revenue goals belong in the business case, not as a substitute for SR&ED technology content.
After-the-fact binders with no project trail
Tickets, prototypes, test logs, and design reviews created during the work are stronger than reconstructed stories at claim time. Capture as you go.
Including standard engineering without a method to exclude it
Not every sprint is experimental development. Document why specific work advanced technology beyond standard practice in the field.
Contractor evidence that does not match T661 technology lines
Keep statements of work and deliverables aligned to the projects you claim. Misaligned vendor packs create review friction.