The Duchess of Cambridge plans to give birth to her second child at the Lindo Wing at St Mary's Hospital in west London, it has been confirmed.
The royal couple do not know the sex of their child, officials also said. It is believed Catherine's due date is in the second half of this month.
Prince George, Prince William and Prince Harry were all born in the wing.
Royal officials say the couple are "hugely grateful" for the warm wishes they have already received.
During the birth of her second child, Catherine will again benefit from the private facility being based within an NHS hospital with facilities for premature babies, and access to hospital specialists.
The Lindo Wing at St Mary's Hospital in Paddington describes itself as having offered "leading private obstetric and neonatal care for 60 years".
It costs more than £5,000 for the first 24 hours of a delivery with an extra £1,000 for each additional night.
It has also seen the births of the children of Princess Anne, the Duchess of Gloucester and Princess Michael of Kent.
Prince George was delivered there at 16:24 BST on 22 July 2013, weighing 8lb 6oz (3.8kg).
Hundreds of reporters, photographers and TV camera crews from across the world gathered outside ahead of his birth.
But BBC royal correspondent Nicholas Witchell said Kensington Palace is hoping the media will not start to turn up this time until it is confirmed that the duchess has been admitted to give birth.
"I think on this occasion the police will move on any reporter, photographer, camera crews and people such as us, who attempt to linger there before it is confirmed that she has gone into hospital to give birth," our correspondent said.
"This is a new way of approaching it but it is symptomatic of this desire that there should not be quite such a level of chaotic interest."
By Peter Hunt, BBC royal correspondent
In the coming weeks the brown door of a private maternity wing will once again become the focus of considerable global attention.
The American networks aren't distracted by a domestic election.
Facts, once again, will be in short supply but that won't deter the broadcasters (including the BBC).
A royal birth, for the monarchy's supporters, is a moment to celebrate.
Its critics view it as a moment to consider whether what they call "this circus" of a hereditary institution is the best way to run things.
For William and Kate a very private moment will, eventually, be shared very publicly.
Their second child will be a prince or a princess. But not, as things stand, a future king or queen.
Prince George will have a new playmate; the Cambridge family will be expanded; and the monarchy's future will be further strengthened.
Babies born on the same day as the royal baby will be eligible to receive one of 2,015 free "lucky" silver pennies.
The Royal Mint has announced it will mark the birth of the Duke and Duchess of Cambridge's second child in the same way it commemorated the arrival of Prince George in 2013.
Parents of newborns who share a birthday with the new prince or princess will have to register the birth of their child on The Royal Mint's Facebook page to receive the commemorative gift.
Succession rule change
Prince William and Catherine's second baby will become fourth in line to the throne, behind older brother Prince George, who is 18 months old.
The second birth comes as new rules on royal succession have come into force, removing male bias and discrimination against Roman Catholics.
If the new baby is a girl, she will follow Prince George and become fourth in line to the throne and will not be overtaken by any future younger brothers.
The Act was passed by Parliament in 2013, but all the countries in which the Queen is head of state had to pass any necessary legislation before it took effect.