JAR-FCL 1.065(e) is the regulation which prohibits to hold two licenses at same time. Is this situation only in one JAR state? So I can't hold PPL and CPL valid at same time in UK, but I can hold PPL in for example in Spain and CPL in UK?
"JAR–FCL 1.065 State of licence issue
(e) An applicant shall hold only one JAR–
FCL licence (aeroplane) and only one medical
certificate at any time."