if you had multiple w-2's causing the excess withholding, do not file form 843 rather Tutbotax will calculate the excess and give credit on your 1040
for penalties, or for any other reason other than an IRS notice or estate tax claim (described above) or Letter 4658, Letter 5067C, net interest rate of zero request, or a nonresident alien’s claim for refund of social
security or Medicare taxes withheld in error (see below) the service center where you would be
required to a file a current year tax return for the tax to which your claim or request relates. See the instructions for the return you are filing
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
page 114
per Turbotax
if one employer withheld too much, contact them and ask for:
- A refund for the excess amount, and
- A corrected W-2 (also called a W-2c), which shows the correct Box 3 and Box 4 amounts
Don't file with excess withholdings on your return, as you may be subjected to penalties and interest.
What if my employer can't—or won't—cooperate?
You can correct the Box 4 amount yourself before filing. Simply multiply the amount in Box 3 by a factor of 0.062 and enter that amount or 9,932.40 (whichever is less) in Box 4.
in some cases where you have to repay compensation an employer will not adjust for the Social Security taxes, or medicare taxes, filing 843 in these cases form 843 is appropriate see what the IRS would like below.
form 843 line 7 instructions
Refund of excess social security, Medicare, or RRTA tax. If you are claiming a refund of excess social security, Medicare, or RRTA tax withheld by one employer, you must, if possible, attach a statement from the employer. The statement should indicate the following.
• The amount, if any, the employer has repaid or reimbursed you for excess taxes withheld.
• The amount, if any, of credit or refund claimed by the employer or authorized by you to be claimed by the employer. The employer should include in the statement the fact that it is made in support of your claim for refund of employee tax paid by the employer to the IRS. If you cannot obtain a statement from the employer, you should attach a statement with the same information to the best of your knowledge and belief and include in the statement an explanation of why you could not obtain a statement from the employer. Attach a copy of your Form W-2 to prove the amount of social security, Medicare, or RRTA tax withheld.
Refund of social security and Medicare tax withheld in error. The same supporting evidence described above must be provided. If you are a nonresident alien, see Pub. 519 for additional information.
