Open with the problem you are solving, not your preferred technology. Which people will use the system, with what frequency, and what happens today? An estimator who grasps the purpose often proposes an alternative that costs less; one who only sees a list of screens prices exactly what you asked for.

Describe the scope as short scenarios: a walk through each important path. Equally important, write down what the first release deliberately excludes. An explicit list of exclusions prevents more argument at delivery time than any other single page. Also mark which parts are firm and which may still change — estimators price uncertainty, and concealing the open questions helps nobody.

Set out your constraints. The list covers existing systems the software development quote has to talk to, the data you already hold and its condition, compliance requirements, user volumes, which devices matter and infrastructure that is already decided. If there is a hard date, say what depends on it: a team can often cut the right scope to hit it, but not if the date is a secret.

Define what done means feature by feature. Clear acceptance criteria need not use formal language: a short list stating the expected behaviour is enough. That one addition reduces the sign-off process by a surprising margin and removes the most common source of disputes.

One last thing, state what you want software development companies in uk the response. Ask for a task-level breakdown, the assumptions behind each number, the risks the team sees and an optimistic and a pessimistic figure. Take a broad range as information, not evasion: it normally identifies the part of the brief that needs work. At that point rewrite that part and request a revised number — the revised figure will be far closer to reality.