I recently sold some stocks, do I need to pay capital gains right away or can I wait until this years taxes get filed in the spring? If I need to pay them now, how do I?

[xmasbaby0]

You will enter your 1099B when you prepare your 2020 tax return.

[Critter-3]

An estimate may be needed ...

What are estimated taxes?

https://ttlc.intuit.com/replies/3301588

Do I need to make estimated tax payments to the IRS?

PAYING ESTIMATES
For SE self employment tax - if you have a net profit (after expenses) of $400 or more you will pay 15.3% for 2015  SE Tax on 92.35% of your net profit in addition to your regular income tax on it. So if you have other income like W2 income your extra business income might put you into a higher tax bracket.

You must make quarterly estimated tax payments for the current tax year (or next 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.)

https://ttlc.intuit.com/replies/3301891

 

How do I make estimated tax payments?

https://ttlc.intuit.com/replies/3301258

[jproffer183]

Thank you!

[Hal_Al]

Simple answer: you can wait until you file your taxes to pay.   

There is usually no penalty for under paying your income tax, in a situation where your taxable income increased from the previous year.

Technically the rule is: You should make 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.