Here is everything you need to know.
What are the designs?
Each of the six new festive stamps depicts a stained-glass design, and the scenes come from windows in churches across the country, covering a range of eras, styles and techniques.
Philip Parker, head of stamp strategy at Royal Mail, said: “Our beautiful Christmas stamps feature the Nativity as told through the artistry of different styles of stained-glass windows.”
All of the stamps feature the infant Jesus being cradled by the Virgin Mary.
Where are the designs taken from?
The 1st Class stamp sees Mary cradling the new-born Jesus in a brightly coloured window from St Andrew’s Church in Coln Rogers, Gloucestershire.
The 2nd Class stamp depicts the ‘Adoration of the Magi’ from the east window of St Andrew’s Church in East Lexham, Norfolk, the round tower of which is said to be one of the oldest in England, built around 900AD.
Another stamp shows the ‘Virgin and Child’ scene from a window in Church of St James in Hollowell, Northamptonshire, known for its stained-glass windows.
The ‘Virgin and Child’ scene is also seen in the £1.70 stamp, with Mary seated and holding the infant Jesus on her knee, taken from a window in All Saints Church in Otley, West Yorkshire.
A stained-glass window from St Columba’s Church in Topcliffe, North Yorkshire shows three scenes in the life of Mary, which also relate to the birth of Jesus; the £2.50 stamp in the series includes a scene from this colourful window.
The final £2.55 stamp shows a section of a window from the Christ Church in Coalville, Leicestershire, which focuses on Mary and Jesus.
The Reverend Gill Pinnington, of Christ Church, Coalville, said she was "proud" its stained-glass window was featured.
The Leicestershire-based cleric told the BBC: "We are very proud of our stained-glass windows and are so happy that the beauty of the Mother and Child can be shared with the nation."
When are the stamps available?
The Christmas stamps are available to purchase from today (Tuesday 3 November).
They will be available in 7,000 post offices across the UK, and also available to order through the Royal Mail’s website.
What are the last post dates for Christmas 2020?
Friday 18 December - 2nd Class and 2nd Class Signed For
Monday 21 December - 1st Class and 1st Class Signed For and Royal Mail Tracked 48
Tuesday 22 December - Royal Mail Tracked 24
Wednesday 23 December - Special Delivery Guaranteed
It’s worth noting that Royal Mail Tracked 24 and Royal Mail Tracked 48 services are not available to purchase at Post Office branches.