This is the FIRS-approved CSV file that payers are suppose fill and upload when making WHT payments.

Corporates would usually make lots of WHT remittance at a go. So, they fill in the details for each payment line by line into the CSV file that I sent earlier.

There's a column in there named "Rate (5% or 10%)", which means this column must either contain the integer value 5 or 10.

So, when a user uploads the file with data in it, the validation that you'll carry out is to check that the value entered into the "Rate (5% or 10%)" column for that record is what is applied to the value in the "Contract Amount" column to arrive at the value in the "Tax Amount (No commas)" column.

So, for example, if "Contract Amount" = 10m and "Rate (5% or 10%)" = 10, then "Tax Amount (No commas)" must be equal to 1m.

You'll have to iterate through all the records in the CSV to carry out this validation on each one.