It's my fault. I went overdrawn last year. They keep sending me the same message.
Your account is in an Unarranged Overdraft
Your Santander account ending **** went overdrawn without an arrangement on 13/10/2018.
You won’t be charged any Unarranged Overdraft charges however if you have any payments due then they may not be paid.
We recommend you pay enough money into your account so that any payments you do have can be paid. Until you pay money in payments could be refused.