I believe the UK has 12 trial aircraft running trial non-operational software and a limited trials weapons clearance, pending even the start of IOT&E testing in 2018. After the completion of which the UK trials will start then OCU training and, supposedly, the training of the first operational squadron with an IOC date for carrier deployment around 2023?
IIRC an agreement has been made for the USMC to deploy onboard to provide a semblance of competence in procurement and purpose.....