Customer has the following situation:
When changes are made to the Business Partner Master Data, it causes a change in the invoice output such that previous invoices sent to the customer will not match the display of the invoice after the change.
One business unit has developed a 'work around' where it stores a PDF of any invoice sent to a customer. This solution is deemed to not be acceptable for the current business unit. The volume of invoices would make it so as to not be practical.
What is a solution to keep the original invoices correct as sent rather than be updated by the Business Partner Master Data change?