APD Increase - what effect will it have?

HI all
with the announcement regarding the increase in Air Passenger Duty, it got me thinking - what about those of us that have already booked and paid for flights?
Does it mean that we now owe a further amount of tax?
Will this affect things like OLCI, because effectively there is now a outstanding balance on the account?
Hopefully some of you more knowledgable peeps will be able to settle these queries!
with the announcement regarding the increase in Air Passenger Duty, it got me thinking - what about those of us that have already booked and paid for flights?
Does it mean that we now owe a further amount of tax?
Will this affect things like OLCI, because effectively there is now a outstanding balance on the account?
Hopefully some of you more knowledgable peeps will be able to settle these queries!