I filed before the unemployment tax credit and owe $1400 but I haven't paid yet. Do I need to amend my taxes to receive the new unemployment tax credit?

No,  If you already filed and didn't get the 10,200 unemployment exclusion you do not need to amend.  The IRS will be adjusting it for you.  See,

https://www.irs.gov/newsroom/irs-to-recalculate-taxes-on-unemployment-benefits-refunds-to-start-in-may

 

If you had a tax due on the original return and haven't paid yet you don't have to pay it.  Wait for the IRS to send you the new refund or a new bill.

Let the IRS adjust your return, if your income will be below $150,000. The IRS will adjust if a credit is  already on the return.

 

If not, you would need to amend for credit. Only amend if the credit is not on your return and should be - after the IRS is done.

 

 

Some credits:

 

Earned Income Credit eligibility:

The greater of AGI or earned income must be less than:

• $15,820 ($21,710 for MFJ) with no qualifying children,
• $41,756 ($47,646 for MFJ) with one qualifying child,
• $47,440 ($53,330 for MFJ) with two qualifying children, or•$50,954 ($56,844 for MFJ) with three or more qualifying children. 

Child Tax Credit

• See What is the Child Tax Credit?  

• You can visit the IRS interactive tool for Child Tax Credit 
• visit IRS Pub 972 Child Tax Credit -page 4 for income details.

 

Education credit, retirement savings and more!