[BNM] Downpayments

[Ali]

Hi

I normally work on a 40-40-20 payment schedule whereby the first 40% is classed as a downpayment and paid upon commencement of work, the next 40% upon delivery and the final 20% upon acceptance (usually 30 days after delivery).

I have run into a client who does not appreciate the principle of downpayments and I find myself having difficulty articulating it concisely. I normally talk about all the risk being mine in the absence of a downpayment and the need for cashflow on projects spanning a few months. 

What I would dearly love one of you good people to point out to me is some form of independent article or report on best practices when commissioning web applications/software/media in general, or failing that a good rendition of the principles albeit from a developer.

Ali