R12.0.x: Patch 17896105:R12.AP.A:1099 CHANGES FOR YEAR 2013: R12 (12.0)
R12.1.x: Patch 17896105:R12.AP.B:1099 CHANGES FOR YEAR 2013: R12 (12.1)
R12.2.x: Patch 17896105:R12.AP.C:1099 CHANGES FOR YEAR 2013: R12 (12.2)
R11i: Patch 17925376:1099 CHANGES FOR YEAR 2013 FOR 11i(11.5.10.CU2/220.127.116.11/AP.O)
Note: These patch numbers were updated on 16th Dec 2013 due to prior patches (R12 - 17842317 and 11i - 17763198) being superseded.
For full details please review the 1099 Document that is updated every year at this time in preparation for the upcoming 1099 tax season:
Oracle Payables Plans for 2013 1099 Reporting (Doc ID 209913.1)