Overview of Transfer Split functionality in LLM can found in this article .
1)Entitle the Source Account (View Account -> Entitle -> Entitle Account)
2)Create an order line (View Entitlement -> Edit Entitlement -> Add Line items with all details) - Certificate from the source account will keep its activation code and will remain ACTIVE
3) Create a Target Account
4) Make sure to check no mappings, splits are active on the source account
5)Check for the Activation Code under Allocations ( View Entitlement -> View Allocations).
Under Allocation Details before Split.
6)Before the Complete Split:
7) After splitting the remaining quantity, we see that the whole quantity is under Target Account with the Activation Code retained.
NOTE : Do this Action in EP if you want an email to be sent to the customer.