What if my client changes their EIN or business information? Do I need a new Form 8655?

Yes, if your client changes their EIN or any other critical business information (such as business name, address, etc.), a new Form 8655 must be filed. The IRS requires accurate information to identify the business and its authorized Reporting Agent. 

Therefore, you will need to submit a new Form 8655 with the updated information to ensure that the IRS has the correct details on record and that you can continue to act on behalf of the business.