There is no magic number
Some jobs need a deposit because materials must be ordered, a schedule must be reserved, or custom work has to begin before anything shows up at your house. Other jobs should not require much money upfront at all.
The better question is not only how much the contractor wants. It is why that amount is needed, what it buys, when work starts, and what proof you receive after paying.
Match the deposit to the job
A small repair, a custom cabinet order, a roof replacement, and a full remodel do not carry the same upfront cost. The deposit should match the real project conditions, not a generic sales script.
Ask which materials are being purchased, whether they are returnable, whether permits are included, and how the deposit connects to the first visible stage of work.
Watch for pressure around the money
A contractor can be busy without making you feel cornered. Be careful when a deposit is tied to a same-day discount, a sudden opening, or a claim that you cannot read the paperwork first.
Pressure does not prove anything by itself. It does mean you should slow down and make the details clearer before money leaves your account.
Put the deposit in the case file
Save the signed estimate, deposit receipt, payment method, text messages, product selections, and any promise about start date or delivery date.
If the deposit is fair, the record protects both sides. If it becomes a problem, the record gives the next conversation a factual starting point.
Sources and limits
These Case Notes offer practical homeowner guidance. Licensing, deposits, permits, and lien requirements vary by location and trade. Confirm requirements with your state or local authority; a document review does not replace legal advice, engineering, or a formal inspection.
For consumer-protection guidance, see the FTC guide to avoiding home improvement scams.