The United States Postal Service provides various options such as Priority Mail Express and Priority Mail for mailing tax returns to the Internal Revenue Service. The best way to mail tax returns depends on the amount of time remaining before tax deadlines.
Priority Mail Express ensures the delivery of tax returns within one to two business days. This option includes USPS tracking and request of a signature upon delivery. Priority Mail delivery takes between one and three business days. This option also includes USPS tracking. Proof of mailing options offered by the USPS include return receipt, certificate of mailing and certified mail service.