Jet2.com and Jet2holidays have suspended all flights and holidays until 25 March.
The announcement means the airline and operator has effectively closed off the current winter season.
“Due to the ongoing uncertainty and travel restrictions caused by the Covid-19 pandemic, we have taken the decision to extend the suspension of flights and holidays up to and including 25th March 2021,” it said in a statement.
It added: “Where customers yet to travel are affected by any programme changes, our approach to providing smooth and speedy refunds has been widely praised by independent travel agents, and we will be automatically cancelling affected bookings with a relevant refund.
“Since the onset of the pandemic, we have always respected that customers should receive their money back if we have not provided their flight or holiday.
“For customers due to travel from 26th March onwards, we will provide our independent travel agency partners with further updates update closer to the time as appropriate.”