Sorry if this sounds stupid but want to know if I put full allowance of �3600 into an isa this month (March)can I then put in more once the next financial year starts in April?
Your total ISA allowance each year is �7,200 of which each year you can put �3,600 into a cash ISA.
What you can't do is put �3,000 into a cash ISA one year and then �4,200 the next year. Each year you either use the allowance in full or or part or lose it.