Pippa Middleton
Pippa Middleton is set to say 'I do' as she weds James Matthews on 20 MayReuters

With the Duchess of Cambridge's younger sister Pippa Middleton set to walk down the aisle in a matter of days, IBTimes UK gives you the lowdown.

When and where is Pippa Middleton getting married?

Pippa will wed banking tycoon James Matthews, 41, on Saturday, 20 May, at St Mark's Church in Englefield, Berkshire.

Who is going?

Around 150 guests are expected to attend including the Duke and Duchess of Cambridge, Pippa and Kate's brother James Middleton along with girlfriend Donna Air, and Ben Fogle and Roger Federer.

Although Prince Harry is invited, his Suits girlfriend Meghan Markle is not believed to have been invited. Some reports suggest she may attend the reception.

James Matthews' younger brother Spencer Matthews – who previously starred in Made In Chelsea – will be there for the big day, but like Prince Harry will be flying solo with girlfriend Vogue Williams not on the guestlist.

Will Kate Middleton be a bridesmaid?

Despite Pippa acting as maid of honour when her sister wed Prince William in in 2011, it is not believed at present that Kate will play an official role in her sister's nuptials.

He son Prince George, 3, and daughter Princess Charlotte, 2, will act as page boy and flower girl.

What wedding dress will Pippa Middleton wear?

The bride is expected to opt for traditional white for her big day and has been spotted shopping with mum Carole, 61, at top-end stores including Suzanne Neville in London's Knightsbridge.

On her website, Neville is described as an "award-winning designer of bridal and evening wear couture fashion, all British hand-made wedding dresses and gowns".

Another designer in the running is Giles Deacon who was seen visiting Pippa's home at the end of last year.

When asked for comment however by the Mail Online, he replied: "Until things are confirmed, it's just rumours."

Who will be best man?

James' brother Spencer Matthews will do the honours.

Where will the wedding reception be?

After the wedding guests will head back to Pippa's parents' house, a sprawling £6 million manor in Bucklebury, Berkshire.

The groom's brother Spencer Matthews will serve as Best ManInstagram