UK net migration in 2022 revised upwards to 745,000 - BBC News
In May, the net migration figure for 2022 was given as 606,000 - that was today revised up by 139,000.
Statisticians at the ONS use a number of different methods of counting people in and out of the country.

But being a net migrant – among that number that shows up in the total – depends on whether a person intends to stay in the UK for twelve months or longer. That is a widely used United Nations classification.

When people arrive here, there is not always enough information to know whether someone intends to stay for 12 months. So the ONS uses estimates based on past behaviour – known as an “early leaver adjustment”.

It is these adjustments which have changed, leading to a backwards recalculation of the previous net migration total.

The adjustments were also applied to the numbers arriving from Ukraine and from Hong Kong on British National (Overseas) visas.

The ONS says that as those schemes opened in the past two years, they do not have enough historical information to make a full calculation.

They have also adjusted for students who arrived but did not leave at the end of their study period – instead switching to a work visa.