EJ- has been available to the Irish Republic for many years, but unused. After all the EI- register is only a little under a third used with in-sequence allocations and currently no reallocations.

At least EJ-**** (4 letters) will visually be different from the current EI-*** (3 letters). As the register is intended for corporate aircraft, presumably 4 letter allows for more word combinations. Following the Manx example there is clear money to be made from Corporate registrations.