I was interested in when, confirmed now for Tuesday
From Tuesday 14 December, people who are fully vaccinated and identified as a contact of someone with COVID-19 – whether Omicron or not – should take an NHS rapid lateral flow test every day for 7 days to help slow the spread of COVID-19
www.gov.uk/government/news/daily-rapid-testing-for-covid-19-contacts-launches-this-week
So not 10 days isolation as for omicron previously