If you hold a low number of credits beyond Foundation, you have two recommended options to transition to ITIL 4, dependent on what you want to achieve in the scheme.
OPTION 1: You are encouraged to take ITIL 4 Foundation and a further module in your preferred area of interest, becoming either an ITIL Specialist, Strategist or Leader.*
If you have no intention of pursuing the ITIL Managing Professional designation, the recommended route for you would be to take the most relevant module in your area of practice/interest.
OPTION 2: You are encouraged to achieve 17 credits from ITIL v3 to become eligible to take the ITIL Managing Professional transition module.
If you would like to work towards achieving the ITIL Managing Professional designation, you will need to continue collecting ITIL v3 credits until you have achieved the required 17 credits to be eligible to take the Managing Professional Transition module.
The benefit of this route is that you are eligible to fast-track past the v3 Managing Across the Lifecycle course and exam. You can also continue collecting credits before ITIL Managing Professional examinable modules are launched.
*further prerequisite required