You may run into this periodically when running the P470412 and wonder why are you getting error 2475 - PO Line already Matched when the line you are attempting to voucher has not been matched? You can inquire on the order/receipt in P4314 (with Match Type = 1) and it pulls in the sub-file data verifying the detail lines are available for / ready for voucher creation. So why do you get this error?
There are a few reasons why you may be getting this error. One of the most common and most missed reasons for this error is you are attempting to create a voucher for a partial receipt and the F47042 field 'No of Lines' (SZNLIN) does not have the correct value.
Details on this answer along with the other possible causes are detailed in WS: 47: Troubleshooting Inbound EDI Transaction Sets (Doc ID 1559493.1).
If you would like even more information on this and other errors as well as general information on the P470412, use the link below to view the recent Advisor Webcast on World program P470412.
Advisor Webcast Recording: JD Edwards World (JDE World) - JD Edwards World SCM Tips for Troubleshooting of P470412 Inbound 810: Invoice with Receipt Match held on April 16, 2019 [Video] (Doc ID 2502711.1).