The main cause of this problem is when the Client’s tax rate has been changed from one percentage to another in Client Entry.
This causes timesheets which have already been submitted to still carry the previous Client tax rate not the updated tax rate.
When changing tax rates for a client, you must check that all timesheets submitted before this change, are updated to the new tax rate. Submitted timesheets will not update automatically to the new tax rate so you will need to update them yourself. You can do this by selecting the timesheet and then selecting the current tax type and clicking Update:
If the timesheet’s sales invoice has been created you can edit the invoice’s timesheet in Invoice Edit by selecting the timesheet the same as above but because you are in invoice edit once you have updated the timesheet click Recreate Document.
If the invoice has been delivered to the client, a credit note will have to be created and then delivered to the client. When creating a credit note the timesheet will then go back to the status of Awaiting Approval. Edit and then validate the timesheet, then you can create the invoice again and deliver it.