941 report mailing address
The mailing address for the 941 report, also known as the Employer's Quarterly Federal Tax Return, is:
Internal Revenue Service Attn: 941 1111 Constitution Ave NW Washington, DC 20224-0002
You can also file your 941 report electronically through the Electronic Federal Tax Payment System (EFTPS) or through the IRS's online filing system, the IRS Online Account.