good question. in most cases, it's the 9 digits in the lower left of a check. however, for direct deposit in some cases banks use a different routing number. you need to contact your bank. if you use the wrong routing number the direct deposit will be returned to the IRS and they will eventually get around to sending you a check at the address on the return.
how long to get a paper check if DD info is wrong! figure 6 to 8 weeks. maybe longer for many reasons.
