"We're a lot more confident than we were at this point last year, which is why we are returning to the (share) buyback," Chief Executive Simon Wolfson told Reuters.
Earlier, Next upgraded its full-year profit forecast for the 2017-18 year after it beat guidance for sales in the run-up to Christmas.
It also said it planned to return a further 300 million pounds ($407.9 million) to shareholders in its 2018-19 year by way of share buybacks, subject to market conditions.
Next shares were up 8.5 percent at 0813 GMT.
(Reporting by James Davey; editing by Kate Holton)