If you file your taxes late and owe taxes, the IRS will generally impose a failure-to-file penalty of 5% of the unpaid taxes for each month or part of a month the return is late, up to a maximum of 25%. Additionally, there is a late payment penalty of 0.5% per month on the unpaid tax amount, also up to 25%. If both penalties apply in the same month, the failure-to-file penalty is reduced to 4.5%. Interest, currently at 8% annually compounded daily, accrues on unpaid taxes from the due date until payment. If you file more than 60 days late, the minimum penalty can be $510 or 100% of the unpaid tax, whichever is less. However, if you are due a refund, there is no penalty for filing late, but you must file within three years to claim your refund before it is forfeited to the government. Filing an extension and paying your tax owed by the original deadline can help avoid penalties if you file later by the extended date. The IRS may also assess separate penalties for failing to file certain required forms. Prompt filing even after a missed deadline is recommended to minimize penalties and interest. In summary, the main risks of filing taxes late are monetary penalties on unpaid taxes, accumulating interest, and loss of refund entitlement if too delayed. It's best to file as soon as possible and pay any owed taxes promptly to reduce the financial impact.