...it same for cash back from Tesco? Lets say I buy items for £25 using credit card and take £50 as cashback on same card from any store which provide cash back facility, do they consider as a single transaction of £75 or two transaction 1. Shopping for £25 , 2. Cash withdrawl of £50. If they consider a single transaction, its intrest free untill my due date otherwise £50 would be considered as cash taken from ATM. I do not know answer yet and thats why its here.

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I am surprised by some financial questions on here !!!!!
any cashback you take from a shop gets added to your bill, end of.

Cashback is only given when presenting a debit card for payment of goods.

Cashback does not apply to credit cards.
(Credit Cards are cash Advance transactions not cash back transactions. )

The excess will be treated as a cash advance and the cash advance terms and conditions will apply. This should be explained in your cardholder agreement, probably in print that will require a magnifying glass to read and likely couched in legalese terms, but it should be there somewhere.

lots of people have put what i consider the right answer - you wont get offered cash back on credit cards for that very reason, debit cards only.

I worked in a supermarket and generally they do not give cash back on credit cards so i do not think you need worry. Should it be possible, but i don't think it is, you pay interest on any cash advance. It is not just a one off interest either- it is payable for the entire time you owe that money.