If you have one W-2 from which too much Social Security was withheld or even
two W-2s from the same employer (same EIN), then the IRS instructions call this
"employer's error" and that the employer should refund the excess. It
will not be refunded on the tax return.
If the amount of Social Security taxes withheld was too much because two
W-2s (from two different companies) put together went over $7,347 (the maximum
Social Security taxes to be withheld for one taxpayer in a year), then TurboTax
will compute the excess amount and refund it to you automatically as a credit
on line 71 on page 2 of the 1040.
Please see Tax Topic 608
at the IRS website.
