The maximum interest that would be paid in a year is 6% of £2500 or £150. My opinion is that it would take a lot of juggling to qualify and keep within the limits and to get that £150 with no charges.
I understand that the particular deal that is being put in current press releases is only open to people who are already paying more than they should for other Santander products.
I believe that, if they really wanted to pay 6% interest, they should simply ask for the money for six months, a year, or whatever and then pay the interest. Instead of this, they dream up a complicated scheme whereby they put big posters on the window saying "we pay 6% on current accounts" then they challenge people to stay within the qualifying rules and virtually nobody ever gets 6% and those that do get their "winnings" capped at £150.
They are currently paying 2.75% on a one year bond.