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Given a passage and a query based on the passage, generate an unambiguous, concise and simple answer to the query from information in the passage. Note that the answer may not be present in exact form.

Tax returns sent after the deadline. You should keep your records for at least 15 months after you sent the tax return. Here are some of the standard limitation periods on tax-related documents, according to the IRS: 1 If you owe additional taxes, keep records for 3 years. 2 If you do not report income that should have been reported, and it exceeds 25% of the gross income on your return, keep records for 6 years. If you file a claim for credit or refund after filing your return, keep records for 3 years from the filing of the original return. If you file a claim for a loss due to bad debt deduction or worthless securities, keep records for 7 years. Keep all employment records for at least 4 years after the tax is due or paid. They help in preparing future tax returns and making computations if you file an amended return. Period of Limitations that apply to income tax returns Keep records for 3 years if situations (4), (5), and (6) below do not apply to you. Keep records for 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later, if you file a claim for credit or refund after you file your return. Keep records for 7 years if you file a claim for a loss from worthless securities or bad debt deduction. Keep records for 6 years if you do not report income that you should report, and it is more than 25% of the gross income shown on your return. Note: Keep copies of your filed tax returns. They help in preparing future tax returns and making computations if you file an amended return. Period of Limitations that apply to income tax returns. Keep records for 3 years if situations (4), (5), and (6) below do not apply to you. Tax returns sent on or before the deadline. You should keep your records for at least 22 months after the end of the tax year the tax return is for. If you send your 2015 to 2016 tax return online by 31 January 2017, keep your records until at least the end of January 2018. Period of Limitations that apply to income tax returns. 1 Keep records for 3 years if situations (4), (5), and (6) below do not apply to you. 2 Keep records for 3 years from the date you filed your original return or 2 years from the date you paid the tax, whichever is later, if you file a claim for credit or refund after you file your return. Keep records for 7 years if you file a claim for a loss from worthless securities or bad debt deduction. Keep records for 6 years if you do not report income that you should report, and it is more than 25% of the gross income shown on your return. Keep records indefinitely if you do ... HM Revenue and Customs (HMRC) may check your records to make sure you're paying the right amount of tax. Tax returns sent on or before the deadline You should keep your records for at least 22 months after the end of the tax year the tax return is for. Example If you send your 2015 to 2016 tax return online by 31 January 2017, keep your records until at least the end of January 2018. Tax returns sent on or before the deadline. You should keep your records for at least 22 months after the end of the tax year the tax return is for. Example. If you send your 2015 to 2016 tax return online by 31 January 2017, keep your records until at least the end of January 2018. Tax returns sent after the deadline You should keep your records for at least 15 months after you sent the tax return. If you owe additional taxes, keep records for 3 years. If you do not report income that should have been reported, and it exceeds 25% of the gross income on your return, keep records for 6 years. If you file a fraudulent return, keep records indefinitely. If you do not file a return, keep records indefinitely. Query: how long to you have to keep tax returns
Output:
You should keep your records for at least 15 months after you sent the tax return.