1) I try to have slightly weird terms so that I don't slot neatly into any standard way of ignoring invoices.

2) Yes, in principle, though (a) it complicated taxes and (b) none have ever taken me up on the offer. You could go to a factor to do it for you though.

3) Unless it's a huge difference, no.

When I started at RBS in 2008, having escaped Lehman Brothers just in time, I was glad that I had been switched to weekly invoicing (without being asked) since RBS' share price halved live while I watched in the first week and I wasn't sure that RBS would be alive to pay me in week 2!