Today's engagement follows last night's glittering appearance at the annual Diplomatic Reception (if you're just joining us Click This Way to see Kate in the Cambridge Lovers Knot Tiara) where the couple joined Her Majesty, Prince Philip and some 1,500 guests for the white-tie event.
ICAP, a leading markets operator matching buyers and sellers in wholesale markets, has run an annual Charity Day for the last 22 years during which it donates a day’s revenue and commissions to a selection of charities.
Since its launch Charity Day has raised more than £120 million for organisations around the world.
A look inside the very festive office.
Royal reporter Rebecca English noted "I'm not sure what William and Kate know what to make of the ICAP charity day".
Under the guidance of the brokers, the Duke and Duchess spoke to a number of ICAP clients to close deals over the telephone. They both appeared to enjoy it immensely.
Rebecca English said Kate was "polite and chatty" on the phone.
An unforgettable photo from the day.
More from the Mail Online:
'One of the biggest deals they were involved with came on the TriOptima Post Trade Area, which clears risk out of the market. Ian Hunt, dressed as Homer Simpson, left Kate speechless when he told her that she and her husband had just conducted a deal with two British banks worth 200 billion Euros each - part of a two to four trillion Euro deal in a huge de-risking exercise across the financial markets.
'Please don't add any extra risk!' begged the Duchess, agog at the figures. 'Does It take a long time to pick this up? Gosh this is just extraordinary.'
William was more bullish: 'Feeling charitable today? Good, just what I want to hear!' Eavesdropping on his wife's conversation with a trader on the end of the phone named Andrew he laughed: 'Catherine, I think you can stop flirting with them now!' Turning to trader Brett Lincoln he raised an eyebrow and said: 'Sorry my wife is just embarrassing me!'
The couple successfully closed deals worth £500 million between banks.
William's patronage Skill Force shared their plans for funds raised.
'Money raised for SkillForce from ICAP Charity Day will fund a new ICAP Route to Apprenticeship programme, for 40 young people aged 16-plus. Based in North West England and North Yorkshire, and launching in September 2016, the programme will help young people to develop the employability skills they need to get on to an apprenticeship.
The programme will run for two days a week, and be targeted at young people who lack the skills to present themselves confidently to prospective employers. Young people will be taught employability skills and receive support for literacy and numeracy, and gain experience of the world of work to improve their prospects for getting on to an apprenticeship and into employment.'
Indeed, it is not the first time William has participated in the annual event. In December 2010, the then newly-engaged Prince secured a £14 billion deal between two major banks during a phone call. Kate was due to attend in 2012, but had to cancel as she was expecting Prince George and unwell with Hyperemesis gravidarum.
|British Monarchy Flickr|
The Duke and Duchess enjoyed a game of ping pong.
The fundraising day attracts A-list celebrities, television stars and members of the Royal family hoping to raise substantial amounts whilst they man the phones. Other royals who have participated include Prince Charles, the Duchess of Cornwall and Prince Harry.
Actress Carey Mulligan raised money for War Child UK today. The organisation works in war torn countries to ensure children get an education.
Statistics from ICAP and their values to ensure donating 100% means 100%.
Kate repeated a teal L.K. Bennett suit she first wore for a visit to Leicester with Her Majesty the Queen in 2012.
The £295 Jude jacket with peplum detail was described as "Beautifully tailored with a nipped waist this jacket features kick pleat detailing at the back and uses a soft wool feeling luxe to touch". The £225 structure Davina dress is beautifully tailored with gentle ruching down one side.
Kate accessorised with her Mappin & Webb Empress earrings and necklace.
|Mappin & Webb|
It appears Kate wore her Stuart Weitzman Power Pumps.
And completed the look with her trusty black suede Mulberry clutch.
As I'm sure you've noticed, Kate's hair has been cut considerably shorter since the last time we saw her. It's quite a change for the Duchess who favours longer hair. I'm quite certain I'll be in the minority when I say I'm not a fan of the cut - I think slightly longer hair suits Kate better. What do you think?
There's several great early videos on Kensington Palace's Twitter Feed including footage of William and Kate playing ping pong. Check out Kate's very cute celebratory dance at the end of the video shown below :)
The Duchess of Cambridge celebrates closing a deal over the telephone at #ICAPCharityDay https://t.co/dI8rcTePSR— Kensington Palace (@KensingtonRoyal) December 9, 2015