Individual Income Tax Service Center This center is a gateway for the services and information that individual income taxpayers will need to comply with the District's tax laws. DC Online Filing is a secure site that provides full calculation of District tax and credits and currently allows District residents to file the D-40 and D-40EZ individual forms for free. This site is available 24 hours a day, seven days a week. The Federal/State E-File program allows taxpayers to file their federal and DC returns electronically at the same time. (Electronic filing does not increase the probability of being audited). Feel free to call or visit our Customer Service Center for additional assistance. Electronic/Online Services   DC Online Filing Federal/State E-File Program Interest Calculator Payment Options Filing Information   Collection Division Common Errors Estimated Tax Penalty Forms/Publications IRS Tax Center for Self-Employed Taxpayer Appeal Rights Frequently Asked Questions   Income Tax Filing Income Tax Payment/Refund Income Tax Special Circumstances State or Municipal Bond Income for DC Individuals Q&A* What's New This Tax Filing Season?