Final letter of demand: Does anyone have a good template they would like to share?
I have some debts that need collecting.
Not a lawyer, but having written them quite a few times before, and given the circumstances, I wouldn't sweat the quality of your prose. They just need to do a few things so however you word them is fine - with one small ethical warning.
Practically, as long as you state specifically what the claim is for (reference to original task and/or invoice), and when specifically you need it paid (day & time Friday at 5pm is always a good one) and give them a reasonable amount of time to make payment (2 weeks would usually be more than enough) you're pretty much there. That covers the actual 'demand' part.
Two things you may want to consider:
1. You may also like to say pay it by this date OR if you have a query regarding the charge, enquire by the date (assuming they haven't already).
2. You will also need to decide on the tone of your letter. If it's all out war, you have nothing to lose, just be short, sharp and shiny. If there is ANY chance at all of getting payment through negotiation, don't be afraid to soften it a little and write like you'd speak to someone you actually like. ie "I know this has gone on a while now and is not ideal for either of us, but I really need to do something to bring it to a close. I'd really appreciate you contacting me to resolve this or if you don't have any queries about the charge, paying by time and date below so i don't have to look at alternative ways of getting it resolved... "