Scenario:
In a payment record, I needed to calculate the sum of subtotals for each invoice.
As part of this, when I tried to load an invoice through script that had no edit option and was subject to withholding tax, I received an error message that said “Warning : This invoice already has a payment applied to it, net of applicable withholding tax. Editing is not allowed for this transaction. For more information contact your NetSuite Administrator.”
Solution:
This is currently an Enhancement under 289884 Edit an Invoice > Click on Save > Warning : This invoice already has a payment applied to it, net of applicable withholding tax. Editing is not allowed for this transaction. For more information contact your NetSuite Administrator.
As a workaround, you may do the following:
1. Delete the related Payments and Credit Memos. Note that the decision to delete records is at the company’s prerogative and responsibility. NetSuite will not be liable for any adverse effects of deletion of records.
2. Undeploy Script: WT Transaction Edit Warning. (Customization > Scripting > Scripted Records > Edit Invoice > Unmark Deployed checkbox for WT Transaction Edit Warning). Note that this may affect Withholding Tax processes.
3. Edit the Invoice to make needed changes.
4. Redeploy Script: WT Transaction Edit Warning.
5. Recreate Payment and Credit Memo.
Attaching suiteAnswer on this issue for your reference.
Administrator role > No Edit button on Invoices in an Open Period