Upcoming deadlines
How to use this calendar
- Self-employed? Watch the four quarterly estimate dates. Missing them adds an underpayment penalty even if you pay in full later.
- S-corp or partnership? Your return is due a month before personal returns, because owners need the K-1s.
- Extended last spring? The extended deadlines in September and October are the last stop before late-filing penalties.
Denver deadlines too
Denver sales and use tax and occupational privilege tax returns follow the city's own monthly, quarterly or annual schedule, based on your filing frequency. Your accountant should have those on the same calendar as the federal dates.
Common questions
What happens if a deadline falls on a weekend?
It moves to the next business day. Federal holidays and IRS disaster relief can also shift dates, so confirm with the IRS when you're close to the line.
Is the Colorado deadline the same as federal?
For individual income tax returns, Colorado generally follows the federal April deadline and offers an automatic six-month extension to file.
Does an extension give me more time to pay?
No. An extension gives you more time to file. Payment is still due by the original deadline, and interest and penalties apply to late payments.