When you apply for the first time, the waiting times for a decision are approximately:
14 months if you apply online
18 months if you submit a paper application.
If you are applying for an extension
When you apply for an extension, before you receive a decision or are asked to provide more information, the waiting times are approximately:
5 working days if you apply online
18 months if you submit your application on paper (calculated from when your previous permit expires).