Major purchase sales tax

If you choose the sales tax deduction, there are two methods you can use.  One is to list all your sales tax from your own records.  This method does not have the "major purchase" addition, you simply add it in with all your other sales tax.  

The other method is the optional IRS method, where the IRS estimates your sales tax deduction based on your income and other facts.  When using this method, you will be asked about extra sales tax on major purchases. 

Sales tax is deducted on Schedule A when you itemize your deductions.  You have the option of deducting sales tax or State and Local Taxes (SALT).  The most that you can deduct is $10,000 ($5,000 if you are filing as Married Filing Separately). 

For instructions to enter your sales tax, review the TurboTax Help article Where do I enter my sales taxes paid?

For more information, review the TurboTax article How to Write Off Sales Taxes.