6c37871c__11_CCP_Installment_Agreements__If_the_reason_box_states_
[Then ...] Verify SSN on IAT. Research IMFOL for account. Provide updated information to IAT administrator and request 3856 voucher letter, if appropriate. [If the reason box states:] 
Account is Not on Master File
Internal Revenue Manual - 5.4.11 CCP Installment Agreements