Carefully check that you have entered your Transaction Account sort code and unique account number correctly first.
Your Transaction Account is held in your name, so the transfer recipient details ('recipient name'/ 'payee') must be your name. This name should match how it appears in your Transaction Account, eg. Joe Bloggs. The payment reference can be anything of your choice.
If you enter these details correctly, it is still possible that your UK bank may flag that this payment is going to a payee that is not recognised.
Some Raisin UK customers with a Santander Nominated Account have advised us that they receive a warning message when attempting to transfer funds. We are currently looking into this issue.