A TAX2018 file is a United States tax return created with the 2018 version of Intuit TurboTax. It contains tax data, which includes personal information, federal IRS tax forms, and one or more state forms for the 2018 tax year. TAX2018 files may be encrypted if saved with password protection since they store sensitive personal and financial data.

TurboTax allows you to import data from your previous tax return into a new TAX2018 document. You can select "Use a tax return that's on my computer" when prompted at the beginning of the tax return process. If you want to import data from a 2017 TurboTax return, select the file with the .TAX2017 extension. You can import data from 2017 TaxACT and H&R Block .PDF tax files as well. You will most likely only see a TAX2018 file if you are using the desktop version of TurboTax, which is available for both Windows and macOS. However, the TAX2018 file may also be exported from TurboTax Online. To export a TAX2018 file from TurboTax Online, click Tax Tools → Tools then select "Save your 2018 return to your computer," which initiates the download of the TAX2018 file (taxReturn.tax2018). You can then open the TAX2018 file in the desktop version of TurboTax. Once you have completed your return in TurboTax, you can either print and mail the tax forms or file the 2018 tax return electronically. The "e-file" process is free for federal returns but usually requires a fee to file state returns electronically. NOTE: Most TAX2018 files are created in 2019 since annual tax returns are filed for the previous year.