I was wondering when you invioce your customers, do you itemize the material used, or just give them a total amount? Does it differ from service calls to just T&M jobs. I know if you bid something, the customer doesn't need to know what the break down is. Currently I just give a total material amount. I installed a can light in an existing ceiling. T&M job, Invoice showed Labor 3hrs @ XXper hour and XX for material= Total amount owed. Then I give a desription of work done. No one has complained yet, but was just wondering how others go about this and how your invioces are structured.
Itemizing you invoice will only lead to unhappy customers when they take your invoice and start pricing each and every item out on the Internet (and of course, they'll forget how much it costs to ship heavy stuff like cable) and "conclude" you "ripped them off" royally.
You're not allowed to make any profit on materials, despite your having to make a trip to the supply house (paying $2.75 a gallon for gas, plus wear and tear on the vehicle) or putting your money up to keep a stock of supplies.
I think you're doing the right thing now, and as LK notes, if it works for you, stick with it. You might even be better off by not even separating labor and materials to avoid the "curiosity" factor, or the "$20 for parts $200 for labor" thing.