Mike I was speaking to some guys at the CCDO who rather than write up a contract, set up a direct debit / standing order with their commercial clients.
That way they can pay, interest free over 12 monthly installments and as these agreements are ongoing, unless the custy cancels it you know you've got them for good.
Do this for most of your Commercial work and you can soon have a nice regular monthly income and none of the hassles of chasing money owed.
Worth considering.
Paul