Can I claim UIF if I retire early?

There is a difference between unemployed, and being retired. The purpose of UIF is to tie over workers who have (involuntarily) lost their job or income due to retrenchment, dismissal, illness or pregnancy. It is implied that these workers will attempt to get back into the job market. If you retire early, you do so voluntarily, with the assurance that you have a pension to support you. So early retirement does not entitle you to a UIF benefit.