What to do if i forgot to add a big purchase in 2022 with $9000.00 in sales tax

Did you itemize deductions for 2022?   Did you enter mortgage interest, medical expenses, charity donations, gambling losses....????   Were you close to having enough itemized deductions to exceed your standard deduction for 2022?   If so, you could amend 2022 to enter the sales tax.   If adding the sales tax does not give you enough itemized deductions to exceed your standard deduction, it will not be worth the trouble since it will not change your refund.

The standard deduction makes some of your income “tax free.”  It is not a refund.  You will see your standard or itemized deduction amount on line 12 of your 2024 Form 1040.

2022 STANDARD DEDUCTION AMOUNTS

SINGLE $12,950  (65 or older + $1750)

MARRIED FILING SEPARATELY $12,950  (65 or older + $1750)

MARRIED FILING JOINTLY $25,900  (65 or older + $1400 per spouse)

HEAD OF HOUSEHOLD  $19,400  (65 or older +$1750)

Legally Blind + $1750

Wait until your original return has been fully processed before you amend, and make sure you have saved a pdf of the original return before you amend. (If you do not save it as a pdf, the amended return will overwrite the original, and the original will be lost forever)

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-already-filed/L4VjJ9BA2_US_en_US?uid=m76mq6z2 

Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.  

You can watch for information here:

https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1