In late February we went to IRS taxpayer assistance center with our federal return (MFJ) and W-7 application for my wife. 6 weeks later our return still hasn't been processed and she did not receive an ITIN. With filing deadline approaching and federal balance due I wanted to file for an extension and make the payment. The issue is that all IRS third party payment processors are asking for her SSN or ITIN which she doesn't have. Because of that I can't make a payment on federal balance due. I don't want to get hit with late filing penalty since I have no idea when she will get her ITIN. What should I do in this situation?