Mortgage figure increases after making monthly payment - why?

CH1

New to this but I’ll give it a go
After I make my monthly mortgage payment I can see online my mortgage balance reducing
When I view it a few days later it has increased. Why would this happen?
I’ve only noticed this after making my last 2 payments but have held my mortgage for many years.

Any help or information would be great

getmore4less

Could be interest getting added.

CH1

The balance increases by 50% of the payment made.
I pay just over £700 a month and figure drops then increases again by roughly £370.
Would this be in line with interest charges?

getmore4less

How big is your mortgage what rate what full term

CH1

115k remaining and 18 years. Full term was 27 years. Not sure of interest rate.

Thrugelmir

Interest is most likely calculated on a daily basis and charged monthly to your mortgage account. Depending on the rate of interest you are paying. Could take up to 15 years for more capital to be repaid than interest charged in a month. Hence why many people overpay their mortgages. Accelerates the process of repaying the debt owed, albeit slowly.

getmore4less

CH1 wrote: »

115k remaining and 18 years. Full term was 27 years. Not sure of interest rate.

Find it.

Post full details of your current deal, you might be able to save some money.
Exact numbers not abouts.