"We will obviously be in close contact with them because there are important issues for us," Andrew Bailey, chief executive of the Bank of England's prudential regulation authority, said.
"It is entirely natural that as an institution your shareholders should demand that you do this assessment. As a private organisation they should do it."
Last month HSBC chairman Douglas Flint said the board has launched a review into moving its headquarters out of the UK.
One reason is a hike in a special tax which is levied on banks based in the UK and is making it increasingly costly to do business.
And another bug bear is new measures due to be set out by the Prudential Regulation Authority (PRA), under which banks are likely to be told to separate their "core" retail and business banking arms from their corporate and investment divisions by the beginning of 2019.
But it's not the first time HSBC has threatened to leave.
In 2010 chief executive Stuart Gulliver said he was so "genuinely concerned" about incoming regulation, he was considering moving its headquarters. And in 2011 it told its biggest shareholders that it was "more likely than not" it would head to Hong Kong.