Ahh right i misunderstood your previous post.I thought you were saying it was better to pay monthly into the ISAYou shouldn't do, you'll get max from the year putting it all there at once... lest I'm off as well!

I am on moneysavingexpert, using the cash ISA calculator.
How come if you put in the maximum amount for a financial year £3600 you earn less interest than say putting a £1000 up front and then paying £260 monthly?

Probably because £1,000 + £260 * 12 is £4,120.
If you put more in you'll earn more interest![]()
Possibly he is only going to be doing it for the last 10 months of the tax year?
Maybe, but the calculator on the site he mentions assumes that he has £1000 at the start of the tax year and pays in £260 for 12 months with the figures he used, which is £4,120 in total.