Will he mainly be calling people on one network? (In which case it might be an idea to look for a deal on the same network.)
I have 4 people in my circle on Giffgaff and we get free calls and texts to each other, subject to a £10 top-up every 3 months for calls/texts to other networks. When my credit builds up too much, I stop topping-up and do PAYG until I get back down to £10, then I buy another £10 top-up.
Er, Giffgaff!Which do you use col?