RFIG21940 | Statutory Residence Test (SRT): Record keeping: The sufficient ties test
From HM Revenue & Customs · Residence and FIG Regime Manual
Where an individual has connections to the UK, such as family, accommodation, work or time spent here, they should keep information and records that will allow them to work out:
In which countries they have spent their days and midnights, for example:
Their travel schedule/details
Booking information
Tickets and boarding cards (including etickets)
If they left the UK to live or work abroad:
the date they left the UK
visa or work permit applications
contracts of employment
If they come to the UK to live or work
the date they arrived here
Visa or work permit applications
documentation relating to when they take up employment, or ceasing their previous employment
When the individual was present at their home or homes, or other available accommodation
How long the individual owned or rented those homes, for example when they purchased, sold or leased those homes
The time their home was unavailable for their use, for example because it was rented out