The clean answer
The best time is before a tax-sensitive event, not after the first notice or investor request. A startup does not always need a large monthly accounting engagement on day one, but it should get CPA review before choices create permanent tax records.
The CPA's role is to coordinate tax deadlines, bookkeeping architecture, payroll compliance, equity records, and decision-ready reporting so the company does not need a painful cleanup later.
Strong triggers
- Founder shares, restricted stock, options, profits interests, or 83(b) questions.
- First employee, payroll setup, contractor classification, or multi-state hiring.
- R&D credit eligibility, grants, investor financing, SAFEs, notes, or preferred stock.
- Revenue recognition, deferred revenue, cap table changes, or acquisition diligence.
What to set up first
- Chart of accounts, bookkeeping cadence, bank and card feeds, and documentation rules.
- Payroll and contractor processes with tax forms and state registrations where needed.
- Equity, board, and tax calendar tracking for 83(b), R&D, annual reports, and returns.
- Monthly reporting that can support taxes, investors, and management decisions.