In my opinion you will need two things: 1)recent leave and earnings statement for you and your wife, detailing taxable wages and income taxes withheld, and 2)download the TaxCaster app, wherein you will be able to enter leave and earnings information to forecast tax owed. From TaxCaster forecast you will be able to claim on W4 step 4c. extra witholdings.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
