You can work while studying in the United Kingdoms to support your expenses. As a tier 4 visa holder, you can work for up to 20 hours per week while the course is in session. You are eligible to work only if your course duration is six months or longer and your university/institute is listed on recognised bodies of higher education.
Work rights for the spouse
Your spouse can work while on dependent visa under following conditions:
You are attending an undergraduate degree course that is longer than six months or a PG degree course longer than 12 months.
According to the newly introduced rule in the UK, the dependant who submits an immigration application on or after 06 July 2018 is allowed to work even if your course duration is nine months or longer.