Hey I messed up on my taxes and put $600 for my first stimulus instead of $1200 can I fix this

[JohnW152]

Most likely, but you may not need to.

If you're saying that you input the wrong amount for the first stimulus you received in the TurboTax Online program, and you haven't already submitted your return, simply type stimulus into the Search box and enter.  Then, if you'll click the link Jump to stimulus, you'll be prompted to enter your amount(s) again.

If you've already submitted your return via e-file, wait to see whether or not it's been accepted. 

• If it's rejected, you can change your return to reflect your proper stimulus.
• If it's accepted, then the IRS will most likely automatically adjust your tax return as a math error, reflecting the correct amount, and you'll receive a notice from the IRS.  If the IRS doesn't contact you about an error, and the refund amount on your return is actually the refund you receive, you'll need to file an amended return.  Please see the TurboTax Help article How to amend (change or correct) a return you already filed for instruction on how to amend your previously-filed tax return.

The IRS requires you to report all relevant stimulus information when you’re filing your return.

[cordeaujoanne]

This is exactly what happened.

[JamesG1]

If you have not received one or more of your stimulus checks, you will receive your payment in the form of a Recovery Rebate Credit on line 30 of your 2020 Federal tax return when you file.

TurboTax will compare your one or two stimulus payment amounts to the computations within TurboTax.  The computations within TurboTax are based upon the information that you have entered into the tax software.  If you are due an additional amount, it will be issued as a Recovery Rebate Credit (RRC) on line 30 of the 2020 1040 tax return. 

If you have e-filed your 2020 Federal tax return and the tax return is accepted by the IRS, you will have to amend your 2020 Federal tax return and correct the entries and calculations to receive the Recovery Rebate Credit.

If you have e-filed your 2020 Federal tax return and the tax return is rejected by the IRS, you will have to correct your 2020 Federal tax return and correct the entries and calculations to receive the Recovery Rebate Credit as well as correct the entries that generated the rejection. 

In TurboTax Online, you are prompted to input stimulus check 1 and stimulus check 2 information under Review down the left hand side of the screen.

You can access your stimulus check choices by following these steps:  

• Down the left side of the screen, click on Federal.
• Across the top of the screen, click on Other Tax Situations.
• At the screen Let’s keep going to wrap up.  Click on Let’s keep going.
• At the screen Let’s make sure you got the right stimulus amount, click Continue.
• At the screen Did you get a stimulus payment? you can update your stimulus check entries. 

See also this TurboTax Help.