Find the Journal Entry batch by running the Account Detail report that lists all posted transactions for the account:
  1. Go to Report Manager.
  2. Select General Ledger for the Module.
  3. Select Transaction Reports for the Category.
  4. Produce the ACDTL report for the account in question.
  5. Find the trace # of the duplicate entry.
  6. In Journal Entry, reverse the batch or make a manual Journal Entry entry to offset the transaction.