Yes, you should pay quarterly estimated income taxes. You should include your SSDI income in your calculation because the income you earn as an independent contractor may cause part of your SSDI benefits to become taxable.
Your Social Security benefits may be taxable if your combined income (independent contractor work and social security) exceed the amounts set forth by the IRS. A single taxpayer with a combined income of between $25,000 and $34,000 pay income tax on up to 50 percent of their Social Security benefit. A single taxpayer with a combined income of more than $34,000 owe income tax on up to 85 percent of their Social Security payments.
Married couples filing jointly with a combined income (including both spouses) of between $32,000 and $44,000 pay tax on up to 50 percent of their benefit. Couples with a combined income of more than $44,000 pay taxes on up to 85 percent of their Social Security checks.
You can use Turbo Tax to calculate your estimated tax payments.
You can prepare 2017 1040-es vouchers using your estimated 2016 income. Select the "federal taxes" tab then "other tax situations." Select "form w-4 and estimated taxes."
Say no to the "adjust how much tax you pay" screen since this screen is about adjusting your withholding from a W-2. Say “prepare now” to the "estimated taxes for 2016" screen. This will ask you about what you expect your 2017 income to be & prepare the vouchers accordingly.
If you have already filed your 2016 tax return, follow these steps to prepare estimated tax vouchers.
Sign into your Turbo Tax Online account.
From the Welcome Back Screen, select Visit My Tax Timeline.
From the list of Some Things You Can Do, select Add a State. You are not going to add a state, but this will bet you into your tax return. From here:
Select Federal Taxes
Select Other Tax Situations
Select Start or Update next to W-4 and Estimated Taxes
