Ensure the business rule is set up to allow this functionality:
    1. In Configuration, click Business Rules.
    2. Highlight Transaction.
    3. Mark the Allow editing of posted transaction attributes checkbox.

    Once the business rule is set:
      1. In Journal Entry, open the appropriate batch.
      2. Open the appropriate transaction.
      3. Select the Attributes tab and add attributes.
      4. Save and Close the transaction.
      5. Save and Close the batch.