In the conversation above, there was a mistake in the formula to distribute the box 14 SQD taxes across the cost basis values for the ESPP shares that were sold in in the tax year (2025).
If there are multiple ESPP stock sales, there will be multiple stock sale line items in the 1099B.
In order to get the total amount of taxes distributed across the cost basis values for each stock sale to match the value in box 14a SQD on the W-2, you need to multiply the ESPP sale tax value in 14a SQD by the number of shares sold in each ESPP sale line item. Then, divide by the total number of ESPP shares sold in in the tax year (2025). You can add up all the ESPP stock shares sold in the 1099B to get this denominator.
Add the associated fractional amount of the 14A SQD taxes for each stock sale to each respective stock sale cost basis line item.
This should distribute the amount of taxes paid for each sale proportionally and the total amount of taxes added to the total cost basis value should equal the 14A SQD tax value.
For example, if you add up all the updated cost basis values and subtract the total value of all the original cost basis values, you should get the value of the taxes paid and listed in 14a SQD in the W-2.
