Widely known as the deadline for personal tax filings, April 15 is also the deadline for owners of businesses organized as C-corporations. 

Ty Shea, the Chief Financial Officer of Circle City Broadcasting, says sole proprietorship owners need to file IRS form 1120 by the April 15 deadline to avoid penalties or fines.    

When paying your annual tax bill, Shea says it is important to stay on top of your quarterly estimated payments and adjust your estimates if your business is experiencing higher or lower revenues. 

Shea says the deadline for other corporations to file their taxes was March 15. He also recommends consulting your tax professional if you need to file an extension or have any questions.