For those having to transfer their licence to another EASA country, the UK CAA strongly recommends to start the process by the end of the year - considering Christmas closure and very high volume of transactions, i dare to say 3 months might be tight.
http://info.caa.co.uk/eu-exit/commercial-pilots/
To enable the CAA time to complete its part in the licence transfer process, the CAA advises that application forms from the NAA need to be submitted to the CAA by January 1 2019. We will endeavour to transfer any application received after this date, but the process may not be completed by 29 March 2019.