You can contact the IRS and request that they change the zip code via an IRS Form 8822. However, the USPS mail sorting should be able to figure out the discrepancy so long as the address you provided is valid within the City/State provided. You can also go to your local post office and fill out an Mail Recovery form. On this, you enter the sender's address, the address that you mistakenly entered, and the correct forwarding address. This will delay delivery by a few days, but should guarantee the mistake is remedied.