There used to be a step on the filing page where the program would ask "do you have an IP pin" but it was hard to find unless you knew exactly what to look for. And, you can only enter the IP pin for the taxpayer there, not any dependents, and it is easy to confuse the 5 digit e-filing pin with the 6 digit IP pin.
The place to go to enter all your IP pins is under the "Other tax situations" tab.
