Unfortunately I am unable to upload an Excel file today.

Let's say the Columns are Date, Deposit, and Balance. Deposit in col B is when you make an additional deposit. Balance in col C is showing you the balance. So if there are headers in row 1, then your data would start in row 2.

Here's the formula for the balance starting in C2: =C1+B1+1

Column B is in pence since you are adding 1 pence per day in col C.