A T17 file is a tax return created by the 2017 version of H&R Block Tax Software, a Windows and macOS program used to complete tax returns in the U.S. It contains any necessary state and federal tax forms for 2017 and personal tax information entered by the user.

When you begin a tax return in Tax Software you can choose to import data from a previous year, whether it be from your H&R Block account or another tax service like TurboTax or TaxAct. If you have no information to import you will be asked to enter your basic information and social security number. The software then guides you as you add other tax information, which includes any 2017 life changes, income, deductions, adjustments, and credits on the federal and state levels. The T17 file is typically created by the tax software when a user saves a tax return. The file allows you to save your tax return progress and resume at a later time. Once you finish your tax return, you can electronically file it directly from the H&R Block software or print and mail the return to the appropriate tax authorities. The T17 file may also be used to create a backup of a tax return for archival purposes. To create a backup in Tax Software select File → Backup Tax Return... NOTE: The file extension appended on to H&R Block tax returns indicate the year of the return. T17 files store information for 2017 tax returns, .T16 files store information for 2016 tax returns, and so on.