The move comes just a week after the airline was hit by increases in its landing fees which went from £1.57 per passenger to up to £6 and could rise to £7.89 per passenger during the summer.
EasyJet said the termination of the airline's phone booking services and the move to an entirely online sales service would cut the cost of processing transactions and would keep the cost of flights low.
Simon Pritchard, Web development manager at EasyJet, said the percentage of sales carried out online rose to 86.1% in January, so the move to an entirely Internet-based sales operation was not a huge leap.
"Once you've achieved 86% of sales online it isn't really a huge jump to 100%. It's not a case of someone 'throwing the big switch'," he said.
The site has advanced significantly since it was set up two years ago, Pritchard said, and he was confident that the existing systems were robust enough to cope with the move.
"We've had to consider the fact that if the site was down for a day, we could lose an important chunk of revenue, so we have very robust disaster recovery systems in place to the effect that any glitch would have no discernible impact on sales," he said.
The airline had also added a monitoring system which would alert the Web team to any potential faults. "It's been a steep learning curve but we're near the top of it," Pritchard added.
Since the site was established, EasyJet has been encouraging customers to move to online shopping by offering its cheapest seats and best promotions exclusively over the Internet.