Greggs said on Wednesday that following a successful trial in London, Newcastle and Glasgow, it had opted to work exclusively with Just Eat, providing sausage rolls and steak bakes, including vegan-friendly versions, as well as sandwiches and sweet treats, direct to customers' doors.
After Birmingham and Bristol, delivery will next launch in Manchester, Leeds, Sheffield and Nottingham in the spring, with a plan to achieve national coverage by the end of the year.
Orders can be placed from as early as 0700 GMT, with no minimum spend, though there is a delivery charge.
Last week Greggs said it would pay staff a special bonus after a "phenomenal" year that included the launch of the vegan-friendly sausage roll and higher-than-expected profits.
Shares in Greggs were up 0.6% at 1408 GMT, taking gains over the last year to 62%, and giving it a market value of 2.5 billion pounds ($3.3 billion).
Just Eat is now part of Takeaway.com after the Dutch firm last week won a 6.2 billion pound bid battle.
(Reporting by James Davey; editing by Kate Holton)