Yes, make the vendor you want to transfer the invoice to a Credit Card Vendor, there is a check box in Maintenance. They just do an invoice transfer in invoice data entry.  On the lines tab there is a little icon you click to enter in the information on the invoice you want to transfer over.

BigLouie Does this work for transactions that have been paid and reconciled, too?

The CC vendor feature is for paying invoices from a different vendor.  It won't move the invoice itself.

You can't really move invoices from one vendor to another.  The "best" method depends on what you want to see on each account.  You can reverse the bad invoice, with zero $ manual payment against a clearing account (so the invoice balance is zero), then post things properly in the correct vendor (with another zero $ manual payment, offset against that same clearing account)... but that is just one approach.

Kevin M The invoice is already paid and reconciled since this was months ago. Will those steps still allow it to work on a paid and reconciled invoice/transaction?

Right now the records are crossing since they were posted incorrectly, so the goal would be to not have the incorrect invoice and corresponding payment show up on the wrong vendor. I understand that there probably isn't an easy fix to make this happen, if at all, I am just wondering if it is possible. 

You cannot remove or edit posted data, period.  You can only add transactions.  (Raw data edits are not recommended, except for correcting technically corrupted data, and you don't have that here).

What I suggested would leave an audit trail for backing out the original transactions from the wrong vendor, and re-creating them in the correct vendor.

That is about the best idea I have (others may have alternate suggestions...), but what you want to see, considering the absolute limitation that posted transactions cannot be edited, is up to you.

Refresh a test company and try different things until you are satisfied with a strategy... then do the same steps in your Live company.