The Day Ahead Internal Bilateral for Market (IBM) always flows in Real Time . As a result, the Day Ahead IBM will accrue Schedule 2 TU charges for each Bilateral Contract Block-Hours. More importantly, IBM transactions that flow from DA to RT are only counted once, in RT, even though their origin may have been DA.
DA IBM does not incur Schedule 2 VM or Schedule 3 charges. This is because the IBM only affects Day-Ahead or Real-Time Adjusted Load Obligation, which is not a billing determinant used in the calculation for those charges.
Reference:
Manual 28 section 3.1.2 "Market Participants may enter into Internal Bilaterals for Market associated with Energy in either the Day-Ahead Energy Market, in which case the transaction automatically carries forward into the Real-Time Energy Market, or just the Real-Time Energy Market."