'has been fully booked' is a perfectly correct and usable phrase in written English. You can use it when you want to emphasize that a certain activity, event, place, etc. has reached its maximum capacity and is no longer available. For example: "Sorry, the flight to Paris on Thursday has been fully booked. Would you like to try another day?".
It has been fully booked every weekend this winter.
In Chaumont, the schools program has been fully booked for the museum's three-month stay.
Since the bank started offering the service last year, the Princess V62 sport yacht has been fully booked every day.
Ms. Rainey, who is 85 and was pepper-sprayed by the police in November, has been fully booked for months.
Almost all the hotels here had been fully booked.
The hotel, which had been fully booked, has been nearly fully canceled.
Some 225 hotels, from Nassau to Riverhead in Suffolk, have been fully booked for the entire week of the Open.
When I feel like I can't trust my brain 100%, Ludwig really comes in handy. It makes me translate and proofread faster and my output more reliable.
Claudia Letizia
Head Translator and Proofreader @ organictranslations.eu