Looks like EI-xxx is quite full..
Nationality and Registration Marks of Aircraft Registered in the State
11. (1) The nationality mark of an aircraft registered in the State shall be the
capital letters “EI” and the registration mark of every such aircraft shall be a
group of three capital letters
or
The nationality mark of an aircraft shall be the capital letters “EJ” and the
registration mark of every such aircraft shall be a group of four capital letters.
The application of the nationality marks “EJ” shall be at the discretion of the
Authority and subject to any conditions or criteria it may specify.
(2) The nationality mark shall precede the registration mark and the registration
mark shall be preceded by a hyphen.
Will be EJ-xxxx soon..