Louis will turn two on April 23 and will have to spend his birthday with only his parents and siblings amid the coronavirus pandemic.
It's been said that William and Kate will give their son presents they bought online as well as a little tea party.
Prince Louis' birthday celebrations
Royal expert Katie Nicholl told OK! Magazine: "Kate won’t let any birthday pass without a celebration.
Kate won’t let any birthday pass without a celebration.
"So even though the family are in self-isolation, she’ll make sure Louis enjoys his day. She tends to organise fairly low-key parties for the children.
"Usually Kate’s parents Carole and Michael are there, along with her sister Pippa and their brother James."
Katie said if the weather is nice, the family are "sure to be out in the gardens".
Katie said Louis "loves being outdoors" and is "happiest when he's exploring the grounds" of their 10-bedroom Norfolk mansion.
She added that Louis' older siblings Prince George, six, and Princess Charlotte, four, will make their own cards for their little brother.
Kate will bake Louis' cake
It's been suggested Kate will "stay up late making Louis' birthday cake if needs be".
The royal tot's nursery at Kensington Palace apparently has a Peter Rabbit theme so that could feature on his cake.
Katie said the whole family, including Louis' grandfather Prince Charles, are communicating via Zoom and Skype.
She concluded that William and Kate will "make sure it’s a less work-intensive day and more of a family day for Louis".
It was recently reported that George and Charlotte have been sending messages to the Queen and Charles amid the lockdown.
"Kate Middleton ensures that Prince George, Princess Charlotte and Prince Louis speak to the Queen, 93, known as 'Gan Gan' and Prince Phillip as often as possible," an insider told Fabulous Magazine.
"The older two talk on the telephone or send chatty videos to Windsor."
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