Robert, thanks for the reply.

>>I take what I would charge them for a one-off system and spread it over 2 years, then work that out as the monthly rental fee (minimum sign-up period 1 year). I charge support separately (for a very small fee), plus mileage if I have to come out. 1 year sounds like a risk, but to slightly change an old Jesuit saying "give me your business for 1 year and I will make you mine for life" - my record is one database that has been running and providing income for 13 years.<<

A couple of things occur to me. Have you ever had a client only pay the rental fee for a year (ie. you did not recoup your development fee)? What happens when the client does stop paying - do they own the software if they have paid for at least 2 years, and/or do you uninstall or disable it in some way?

>>Better not tell you any more...even if you are a long way away!<<

Not for long! Seems like Perthshire's full of potential clients - I'm on my way...

Regards,
Alan