An IRS CP14 notice demands payment of an assessed tax balance, but the amount should be verified before you pay or enter a payment arrangement. Missing payments, incorrect tax year applications, prior adjustments, penalties, and interest can all affect the balance.

An IRS CP2000 notice proposes changes when third party tax information does not match a filed return. Before agreeing or paying, determine whether the IRS correctly accounted for basis, expenses, prior reporting, corrected information, penalties, and the actual tax treatment of the transaction.