Im claiming a home office on taxes. which is my gross salary box 1 (wages) or box 3 (soical security wage)?

Answer 1

From your question, it appears you are an employee with a W-2.

If your income connected with the business use of your home is on a W-2, it would be Box 1.

Some good examples are written in Pub 587 which may help you.

http://www.irs.gov/publications/p587/index.html

Answer 2

Neither, actually.

Box 1 shows your wages after deductions for pre-tax items such as retirement fund contributions, health insurance, and cafe benefit plans.

Box 3 shows your total wages before any of those deductions since SS taxes are assessed upon all wages without deduction for pre-tax items but SS tax is limited to the first $97,500 in wages. If your wages are higher than that, box 3 would show the maximum taxable wage for SS taxes.

Therefore, neither box 1 nor box 3 is the correct answer.

Box 5, however, shows your wages subject to Medicare taxes. That amount is not subject to deduction for pre-tax items and is not limited by a wage cap so it will show ALL wages paid.

Of course, if you had other earned income from self-employment activities, that would not show up on any Form W-2 and would need to be added to any W-2 amounts from box 5 of all Forms W-2.

Answer 3

Bostonian answered your question correctly. But what does that have to do with a home office deduction? If you're planning to deduct home office expenses near the total of your income, expect an audit - you mght as well just attach a letter to your return asking the IRS to call you to set up an appointment for an in-home audit. Home offices are one of the items that are heavily abused, and therefore draw IRS scrutiny, so be sure you have the legal right to claim whatever you show.