How will you consider a mistaken credit by the bank in the previous year debiting in the current year?

If the mistake hasn't been noticed either by the Accountant or the Auditor, then where did the entry was reflected in the financial statements?  There will be two possibilities

A- The mistake has affected the Profit and loss account, 

                          Then -  When the entry has been reversed by the bank, 

                                       The accountant should make the adjustments in the prior years Profit 

A- The mistake has affected the Balance Sheet  account, 

                          Then -  When the entry has been reversed by the bank, 

                                       The accountant should reverse the entry and the  same account should be adjusted.

It will not take place simply like that. The bank Reconciliation is a must practice that every accountant should do by month end. If the mistake couldn't identify either by the accountant or auditor , then where it took place ?.There is no short cut in accounting , accountant must go everything  in detail.

Agree Mr. Wajid Ali

Same will reflect in Bank Reconciliation in previous year and when bank debited in current year that will be nullified.

If accounted in the books under suspense a/c  in previous year that will be reversed in current year.