I never ask for payment in advance , you have to build up a trust for a customer , i have worked in the industry for to long now and have seen all trades be ripped off by the customer its not always the trades man ripping off the customer its the other way round and in the past i have been ripped off for over 10 k for a hotel i rewired never got a penny even after going to court which was a waste of time and money the guy declared him self bankrupt , so the vat man and the tax man got there be me nothing so since then i work honestly first fix then payment 2nd fix then payment , its the only way to trade as it only takes a few customers not to pay and you have gone bust , i did work for a company who had 2.5 million of work on the books three companies didnt pay the went bust making 60 guys redundent need i say more