When do Santander credit monthly repayment to mortgage account?

CarterUK73

Our monthly mortgage payment is made around the 5th of each month. It’s a repayment mortgage but I don’t see the outstanding balance on the mortgage go down until the end of the month. Would Santander be holding on to it and maybe earning interest? Think I’d like to switch towards the end of the month if that’s the case?

strawb_shortcake

I'm with Santander and my balance is updated on the 1st same day as payment is made. The only thing I've found is that the date sometimes is wrong so on 1st February it'll show me that my balance has reduced but it will still show the date of 1st January.