Excel sheet

I wanted help to create a simple excel sheet please.

Our current process.
We download a list of names and invoices into a csv file
paste them into an excel sheet.
Then check them to each individually to ensure the person has paid.
If the person has not paid we manually copy the payment to another sheet
We total the amount.
add this total to to another sheet in the workbook.
manually calculate for the first £500/day earnt we pay 45% and for the amount above we pay 50%.
then we have a list of deduction.

Problems
- too many sheets within work book as we have 8-10 individuals each requiring 2 sheets
- not many of the calculations are automated
-too many cells open for errors to occur

can you help design an updated sheet which is more automated.