The NHS vaccination programme will offer every adult the chance to book a COVID-19 booster vaccine by the end of the year in a race to protect people against the Omicron variant.
Online bookings are available for all those in their 30s and above from today.
The national booking service will then open up to everyone aged 18 and over from Wednesday this week.
The NHS is prioritising bookings for boosters and is urging people to book a slot to guarantee their vital jab.
Some vaccination sites may offer a walk-in service for 18s and over from Monday if they have spare capacity.
The NHS has asked every local area to dramatically increase the number of appointments they have in place for vaccinations.
Over the next week, opening hours for vaccine centres will be extended and every area of the country should have centres available that are open seven days a week.
More pop-up sites will be coming online with local areas looking at the most convenient sites for their communities – from trucks and buses in parks and shopping centres to sports stadiums and leisure centres.
GP teams will be asked to clinically prioritise their services to free up maximal capacity to support the COVID-19 vaccination programme, alongside delivering critical appointments such as cancer, urgent and emergency care.
This might mean that for some people, routine appointments are postponed as part of the national mission to roll out boosters.
NHS chiefs are urging people to not delay their booster and book their jab in the run up to the Christmas break.
The NHS has advised that the best way to get your booster quickly is by booking online or by calling 119 but if walk in centres have capacity to do so, they can vaccinate adults aged 18 and over immediately.