The Internal Revenue Service has lots of different addresses for different types of documents being mailed. Here's links to IRS pages on the IRS Web site with the relevant mailing addresses:
- Addresses for sending in a tax return (Form 1040 and related tax forms)
- Addresses for sending in extension forms (Form 4868)
- Addresses for sending in estimated tax payments (Form 1040-ES)
- Addresses for sending mail via a private delivery service (such as DHL, FedEx, or UPS), and be aware that the IRS recognizes only certain types of private delivery services for the purpose of determining whether a tax return was mailed on time.
It's best to send tax-related documents using certified mail with return receipt requested. That way, you'll receive confirmation that the IRS actually received your documents or payment. And this can come in very hand if the tax return or payment gets lost, as you'll have proof of delivery. The United States Postal Service Web site has additional tips for making sure your tax returns are mailed properly.
These links have been updated for the IRS's re-designed Web site.