You cannot change your ZIP code, or anything else on your tax return, after you've filed it.
However, while it is not ever possible to be absolutely, positively, 100%
sure, this probably should not delay or impact your tax refund in any
way. As long as your name, Social Security Number (SSN) and other tax
data on your return are correct, then an incorrect (or mistyped) postal
ZIP code alone should not matter.
In fact, if you filed in
such a way as to request an electronic tax refund sent directly to your
bank (or anything other than a paper check), then the IRS wouldn't even
need to look at, or use, your ZIP code at all. They will just use your
bank account and routing numbers. Only in the instance if they were to
mail you a paper refund or a letter would the ZIP code ever be used by
the IRS. And even in that event, as long as your street address (e.g., 1234 Easy Street), city, and state are correct, then the IRS can standardize and correct the ZIP code as they may need.
In
fact, the USPS (Postal Service) has such a free tool for correcting and
finding accurate ZIP codes on their website.
https://tools.usps.com/go/ZipLookupAction!input.action
Certainly, the IRS is
smart enough to use that, or a database very similar, should the need
arise.
In other words, you should not worry about this. Typographical errors happen all of the time.
Thanks for asking this question.
