The only difference is in the amount of logged coaching that is required post-course. If you want to achieve the Certificate, you need to complete 20 hours of logged coaching with 2-3 people. For the Diploma, you need to complete 60 hours of logged coaching with 6-9 people.
This is why the course dates are the same for both the Certificate and Diploma. Delegates attend the same course whichever qualification they are working towards – it is just the post-course coaching hours which are different.Click here to learn more about ILM