Corrected text: It's been a long time since I had signed in and I have forgotten whether or not it (ITC credit) can expire? If anyone knows, please let me know how to check it. Thank you :)
How to check the expiration of ITC credits (yes, they *do* expire):
From ITC Payment Account, go to Account Details. This will give you the date of the transaction. The credits expire a year from that date.