Jackie m hasn't given a link to his or her recommendation but Santander's offering for an instant access ISA is 1.6% provided you have at least £500 to start with. After a year that goes down to 0.5%. Not exactly impressive. Their customer service is also crap, as I know from my mother who has her current account with them. She only sticks with them because of their 123 current account which she does rather well out of. Perhaps Jackie m is referring to this, but it is NOT an ISA.
Santander has the best and highest interest rate and it is a basic current account - friend recently looked around at all the ISA accounts and found this one in Santander bank, Good Luck
http://www.thisismoney.co.uk/money/savin...
Anyone much about ISA's?
Looking for the best rate ISA on the market?
Not one that your money is locked away for ages. Ages all the time but better interest rate than my bank which is currently 0.75%