If you are unable to file your Colorado individual income tax return by April 15th, you may still take advantage of the state's automatic six-month extension of time to file. There is no form, paper or electronic, to fill out and no need to notify the Department of Revenue that you are taking the extension.
The extension applies to filing the Colorado tax form, not to any state income tax you may owe.
If you expect to get a refund this year but do not make the April 15 filing deadline, you can still file your state form on or before October 15.
But, if you owe state income tax, 90 percent of your tax liability must have been paid on or before April 15 to avoid penalties. Any remaining balance due would be subject to interest only.
Individual taxpayers who owe state income tax should send in their payment with the "Payment Voucher for Automatic Colorado Extension for Individuals" (DR 158-I). The voucher is in 104 Colorado Form 104 income tax booklet. Visit the Colorado Income Tax Forms page to obtain forms.
Mail the voucher to:
Colorado Department of Revenue
1375 Sherman St.
Denver, CO 80261-0008
If no payment is due, do not use Form DR 158-I. File the appropriate forms from the 104 book.
Penalty and interest charges on tax owed:
- When at least 90 percent of the tax owed is paid by the April 15 deadline, taxpayers are charged interest only and avoid penalty charges as long as the income tax filing (electronic or paper) and balance owed are sent by the October 15 extension deadline.
- Those who pay less than the required 90 percent of the amount due on or before April 15 will be charged interest and penalty on the unpaid balance.
- The 90 percent amount applies to corporations as well as individuals.
For other interest and penalty rates for prior taxes years, see Interest and Penalty-Interest Rates.