Details of the UKRI guidance on sick leave (as well as annual leave) is available here (in particular, see TGC 8.2 on page 16 of the document): UKRI-16112023-UKRI_Training-Grant-Terms-And-Conditions-Guidance-November-2023.pdf. Key points from this guidance are:
TGC 8.2 Sick Leave Award payments must continue during absences covered by medical certificates for up to 13 weeks within a rolling 12-month period, additionally the Studentship must be extended by a commensurate period. This means that if you have a health issue, you can take this period of leave without suspending studies and without losing your stipend, if you are able to provide a suitable medical certificate. The commensurate amount of time is then added to your studentship.
TGC 8.3 Annual Leave Reasonable paid holidays, a minimum of 30 days to a maximum of eight weeks per year to include public holidays is recommended and should be allowed for by Supervisors (pro rata for part time Students). Students undertaking work in collaboration with non-academic partners are expected to consider their obligations to those partners in planning leave.
University guidance
University of Liverpool
Details regarding absences are available in the PGR handbook: (see page 26, Chapter 7: When Things Change). Also details of local support are available in your local institute PGR handbook.
University of Sheffield
Several details are available online:
Leave of absence information: https://www.sheffield.ac.uk/rpi/pgr/manage/leave-absence
Working, holidays and placements: https://www.sheffield.ac.uk/rpi/pgr/manage/working-and-holidays
General information for UKRI-funded students, including suspending studies: https://www.sheffield.ac.uk/rpi/pgr/scholarships/award-holders/information-ukri-scholarship-holders
University of York
Details regarding absences are on the YGR webpages: (for ill health see https://www.york.ac.uk/students/health/self-certification-illness/ and for holiday entitlement see https://www.york.ac.uk/research/graduate-school/support/).