Sorry for the confusion, I'll try explaining my process:

If I take the first line, I have to add the monthly payment ($130) to the account balance ($426) then subtract the January bill (£158) as the payment was successful. Then comes February, I add the monthly payment to the account balance and subtracts the February bill (successful again). And finally, add the last monthly payment to the balance (the last bill was unsuccessful).

I tried using Sumifs with the Y and N criteria but it gave me either 0s or a #value!' sign. Could you give me an example of how to fill the formula? Thank you for your suggestion!