ITIN and Federal Tax Return---Help!!!!!! I applied for my Wife's ITIN on April 5th, I got it approved on May 7th. The process is 1.) IRS would first work on the ITIN application if you are filing for a joint return, it usually takes 4-6 weeks for a ITIN number to be assigned. 2.) Once the ITIN number is assigned, only then the filing for tax refund will be processed, this should take another 4 weeks. |