Hello Rgonzalez2,
I get the voiding the bills part, but what do you mean by outstanding checks? Is there checks that were written to pay bills that have not cleared the bank and need voided?
I would not do a Journal entry for these. What I would do is issue a credit in the current year to offset the bills that need voided, and then apply the credits to the bills to get them out of A/P. Code the credits either to the original posted accounts or to a write off account.
On the uncleared checks, I would just create a deposit for the same amount into the bank they are written from and then clear them out during reconciliation. The deposit would be coded to the same account the bills were posted to or to a write off account.
This would show a reversal of the transactions from previous years to the current year, thereby not affecting the previous year's data.