The best accounting firms for startups are the ones a founder never has to explain the company to twice: they work in the software the startup uses, they expect a monthly close and read it, they file the returns and claim the R&D credit without being chased, and they answer the entity and state questions before they become expensive. What they do not do, and should not be paid to do, is keep the ledger day to day or read the runway; that is a bookkeeping service and the founder's own record, which the free payroll for startups calculator on this site works.
Judge the firm on the filings and the credits, not the brand
A startup's firm files the federal and state returns, prepares the R&D credit claim where the work qualifies, handles sales tax and state nexus as the company sells across states, and prepares for an audit if an investor requires one. Ask which of those it does routinely for companies of your size, and what each costs; a firm whose startup clients are all far larger will price and staff the work for them.
It has to work in your software and read your close
A firm that asks for a spreadsheet export every quarter is a firm that does not work in your accounting software; ask which ones it supports and whether accountant access is free. The firm should expect a closed month and read the profit and loss from it, with payroll booked as the loaded cost; a firm that rebuilds the ledger before every filing is charging for bookkeeping at a firm's rate.
Keep the runway record yourself
No firm reads the runway monthly unless it is paid to, and by then the number is a month old. Work it from the closed month with the calculator on this site, keep each reading and each hiring scenario in Pro, and hand the firm the record rather than the question. The best firms prefer it that way.
Questions people ask about best accounting firms for startups
What separates the best accounting firms for startups from the rest?
They work in the startup's software, expect and read a monthly close, file and claim without being chased, and price the work for a company of the startup's size rather than for their largest client.
How much should a startup pay an accounting firm?
A fee for signatures and judgement, not for bookkeeping; if the firm is categorising transactions, a bookkeeping service does that for less and the firm reads its close.
Does the firm tell the board the runway?
Not unless it is engaged to; the runway is the founder's monthly reading from the close, which the calculator on this site works and Pro keeps.