“The PM is officially moving in today and, yes, his partner will be living there,” a spokeswoman mentioned on Monday.
She added that “there won’t be any additional cost to the taxpayer” from Ms Symonds dwelling in Downing Street.
Ms Symonds, a 31-year-old former PR leader, has been relationship Mr Johnson for 18 months.
She made an look in Downing Street final Wednesday all the way through Mr Johnson’s first deal with to the country after formally turning into high minister.
The new PM is travelling to Scotland on Monday in a bid to renew “the ties that bind our United Kingdom”.
In his first authentic discuss with north of the border since taking workplace, he’ll announce a £300 million investment pot for communities within the devolved international locations – an enlargement of regional Growth Deals in portions of Scotland, Wales and Northern Ireland.
Speaking forward of his discuss with to an army base on Monday, Mr Johnson mentioned: “Our Union is essentially the most a hit political and financial union in historical past. We are a world logo and in combination we’re more secure, more potent and extra filthy rich.
“So as we get ready for our brilliant long term after Brexit, it is vital we renew the binds that bind our United Kingdom.
“I’m proud to be in Scotland today to make clear that I am a passionate believer in our great Union, and I look forward to visiting Wales and Northern Ireland to ensure that every decision I make as Prime Minister promotes and strengthens our Union.”