Reconciled checks cannot be voided. To correct the bank register balance:
 
  1. In Banks, under Cash Management Tasks, click Create a new adjustment
  2. Complete the appropriate information on the General tab
  3. On the Distribution tab enter the reversing entry for the original check
  4. In Banks, under Administrative Tasks, click Post adjustments to General Ledger
  5. Complete the information on the posting wizard, and click Post Now