Can I add ratings to a NNPL?
Available Ratings:


  You can add class ratings to the NPPL to allow you to fly microlights, self-launching motorgliders (SLMGs) and simple single-engine aeroplanes (SSEAs).


The above are the only available ratings for an an NPPL. An NPPL (and LAPL) is strictly a VFR license, therefore you could not get rated for IMC. However, you can continue your training to receive your PPL, at which point you could recieve a rating for IMC, which would be your IR(R), or Instrument Rating Restricted. 

Most flight instructors will provide basic IMC training just in case you find yourself in a bad situation, which can happen to even the most cautious pilots.