Open with the problem you are solving, not a feature list. Which people will use this, with what frequency, and how is the job done today? An experienced team who understands the goal can propose an alternative that costs less; one who only sees the requirements as given prices your assumptions along with the work.
Define what is included as concrete flows: what the user does fintech and crypto software development company what the system does in response. Just as important, write down what the first release deliberately excludes. An explicit list of exclusions saves more argument at delivery time than almost anything else in the document. Also mark which parts are firm and which are still under discussion — honest teams fixed price contract software development those differently, and concealing the open questions only hurts you.
Set out your constraints. This means systems you must integrate with, existing databases and their quality, compliance requirements, traffic expectations, target platforms and any technology you are committed to. If there is a hard date, say why: a team can often resequence the work to hit it, but not if the date is a secret.
Write down what the word done means for aso agency the important items. Acceptance criteria need not use any formal notation: react native consulting services a short list stating what a user should be able to do is sufficient. This one section shortens the sign-off process by a surprising margin and closes off the most common source of disputes.
One last thing, ask for a specific format. Require a breakdown by feature or module, the assumptions behind each number, whatever the team considers risky and a low number and a high number. Read a wide range as a signal about the brief: it usually points to exactly which requirement is unclear. From there clarify that area and request a revised number — the revised figure is far closer to reality.