I've noticed recently that I've had a minority of customers that usually send cheque payment(literally 1/2 but still very frustrating), neglecting to put a stamp on the pre-addressed envelope. Now petty as this sounds, it results in a major hassle trip to my nearest(out of the way) Post Office and a £1.50 charge. Now I realise this isn't a vast amount of £££, but when you deduct charge/fuel/time from the cost of the job it becomes a concern. So with a view of being diplomatic, what's the best way to handle this situation? Politely worded message on next bill adding cost, or politely worded message on next bill excusing this one time? Any suggestions- i dont want to start losing £££(however small) as I'm still building round and every penny counts, but don't want to lose work through pettiness/mis-understandings?