If you have W2 income and withholding it may be enough to cover the self employment tax or you can increase your withholding to cover it.

You must make quarterly estimated tax payments for the current tax year if both of the following apply:

- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.

- 2. You expect your withholding and credits to be less than the smaller of:

    90% of the tax to be shown on your current year’s tax return, or

  100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months).

Turbo Tax will calculate the 1040ES estimated payments

https://ttlc.intuit.com/community/tax-payments/help/can-turbotax-calculate-next-year-s-federal-estim...

How to make the Estimated payments

https://ttlc.intuit.com/community/tax-payments/help/how-do-i-make-estimated-tax-payments/00/25875

Here are the blank Estimates and instructions…..

http://www.irs.gov/pub/irs-pdf/f1040es.pdf

To prepare estimates for next year you start with your current return, but be careful not to change anything.  For Online returns, if you can't get back into your return, Click on Add a State to let you back into your retun.

You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.

Or Go to….

Federal Taxes or Personal (Desktop H&B)

Other Tax Situations

Other Tax Forms

Form W-4 and Estimated Taxes - Click the Start or Update button

The 1040ES quarterly estimates are due April 15, 2021, June 15, Sept 15 and Jan 18, 2022.   Your state will also have their own estimate forms.

Or you can pay directly on the IRS website https://www.irs.gov/payments

Be sure to pick the right kind of payment and year.....2021 Estimate

Some general info on self employment and tax..........

You will need to keep good records.  You may get a 1099NEC at the end of the year if someone pays you more than $600 but you need to report all your income no matter how small.  You might want to use Quicken or QuickBooks to keep track of your income and expenses.

There is also QuickBooks Self Employment bundle you can check out which includes one Turbo Tax Online Self Employed  return....

http://quickbooks.intuit.com/self-employed

When you are self employed you are in business for yourself and the person or company that pays you is your customer or client.

To report your self employment income you will fill out schedule C in your personal 1040 tax return and pay SE self employment Tax.  You will need to use the Online Self Employed version or any Desktop program but the Desktop Home & Business version will have the most help.

Here is some IRS reading material……

IRS information on Self Employment

http://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Self-Employed-Individuals-Tax-Center

Pulication 334, Tax Guide for Small Business

http://www.irs.gov/pub/irs-pdf/p334.pdf

Publication 535 Business Expenses

http://www.irs.gov/pub/irs-pdf/p535.pdf

You pay Self Employment tax on $400 or more of net profit from self-employment in addition to any regular income tax.  You pay 15.3% SE tax on 92.35% of your Net Profit greater than $400.  The 15.3% self employed SE Tax is to pay both the employer part and employee part of Social Security and Medicare.  So you get social security credit for it when you retire.  

Hello cahil938!

Let me give you guidance directly from the IRS. This is the best site to help you in understanding your situation with a proposed supplemental income.

If you work as an independent contractor, you should pay 'quarterly taxes' on that income.' Here is the schedule of how to determine when the payment is due and on what amount of money.

https://www.irs.gov/pub/irs-pdf/f1040es.pdf  (page 3 tells you the dates).

This site tells you where to go to make payments...EFTPS. Link is  https://www.irs.gov/payments/eftps-the-electronic-federal-tax-payment-system 

This is the IRS site for self employed. https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center 

The W-2 income already withholds taxes for that income. So, this is different from the self employed income which will be a 1099-MISC or 1099-NEC.

Using our TaxCaster tool https://turbotax.intuit.com/tax-tools/ will help you determine what your tax liability should be for the tax year.  Try to be as accurate as possible to get the most accurate answers. In general, the more you earn, the more taxes you pay. A good estimate will only minimize the amount you owe, if any. But since you have no idea how much you will make in 1099-income, it might be hard to calculate your tax liability.

I hope you find the above information helpful. 

Thank you for using Turbo Tax!!