There is a difference between unpaid employment (voluntary work) and volunteering, and you should always check with the organisation which offers you a volunteering opportunity whether it can be regarded as unpaid employment. This is because the time you spend doing unpaid employment counts towards your maximum number of hours of work a week. Student Route Guidance can be found at Student route: caseworker guidance - GOV.UK
Students can volunteer while they are studying. Voluntary work is distinct from volunteering.
A Student can do voluntary work if they are permitted to work, but this work and any paid work must not exceed the total number of hours they are permitted to work during term time. For example, if a student is permitted to work 20 hours a week during term-time and has paid work of 15 hours a week, they cannot do more than 5 hours of voluntary work. If they are not permitted to work, they cannot do voluntary work.
Factors to take into account when considering whether a particular activity constitutes voluntary work or volunteering are:
• Voluntary workers will usually have contractual obligations to perform the work (for example, to attend at particular times and carry out specific tasks), with the employer being contractually required to provide the work – the contract does not have to be written - the worker is usually remunerated in kind
• Volunteers do not have a contract - they must not be a substitute for an employee, and they must not be doing unpaid work – for example, receiving payment in kind (although they are sometimes reimbursed for reasonable travel and subsistence expenses)
• Volunteers usually help a charity or voluntary, or public sector organisation
This is not a definitive explanation of international student volunteering. For more information, please look on the UKCISA website: UKCISA - international student advice and guidance - Student work.