The EASA licensing system
Pilot licensing regulations are being standardised across all member states of EASA (the European Aviation Safety Agency), including the UK. A number of new pilot licences have been introduced which replace licences issued by national authorities across Europe. These licences are known as EASA licences or Part-FCL licences, and have been mainly introduced by European Part-FCL legislation.
A JAR licence will continue to be valid until its expiry date but cannot be renewed. Expired JAR licences will have to be converted to an EASA licence. After the deadline, it will only be possible to fly EASA certified aircraft if you hold an EASA licence.
You will not lose your licence if you do not convert by 8 April 2018. If you hold a JAR licence, you will not be able to exercise the privileges of your licence until it has been converted to the EASA format. Lifetime UK PPLs will still be valid to fly Annex II non-EASA aircraft, subject to holding the minimum level of medical required and a valid rating. However, any privileges to fly EASA aircraft will be lost.
Your NPPL (A) SSEA or SLMG must have been issued by the UK CAA on or before 7 April 2018.
Holding an EASA licence will entitle you to fly EASA registered aircraft. They are also valid for life, whereas JAR licences required renewal every five years.
It is recommended by the CAA that pilots submit their applications early: The CAA cannot guarantee they will be able to process last-minute applications in time for the deadline, which may result in the grounding of a pilot.