Begin with the problem you are solving, not your preferred technology. Who will use this, how many times a day, and what happens today? An estimator who knows what you are trying to achieve often proposes an alternative that costs less; one who only sees a feature list can only price the list as written.
Define what is included as user stories or scenarios: a walk through each important path. Every bit as useful, write down what you are not building. A written out-of-scope list saves more friction during acceptance than any other single page. Mark too which items are decided and which are still open — honest teams price those differently, and concealing the open questions helps no one.
List the constraints. These include existing systems the affiliate software development company has to talk to, the data you already hold and its condition, regulatory obligations, traffic expectations, target platforms and any technology you are committed to. If a deadline is real, explain what drives it: a team is usually able to resequence the work to protect it outsourcing russia, provided they hear about it early.
Say what done means for each item. Acceptance criteria do not require formal language: a plain-language note setting out what a user should be able to do will do. That one addition shortens acceptance testing by a surprising margin and closes off the most common source of disputes.
To close, ask for a specific format. Request a breakdown by feature or module, the assumptions used, the risks the team sees and a low number and a high number. Read a wide range as information, not evasion: it normally identifies where your description is thin. From there clarify that area and ask for a new estimate — the next version will be much more reliable.