I am currently a master's student and as a result of the confirmation I received from my school and the research I have done, I have the right to work for 20 hours during the academic calendar and 40 hours during the summer holidays. They stated that I have such a right as I am not in the thesis period. I started my first 20-hour part-time job in March and started my second 20-hour part-time job in June, since my school is on summer vacation. I work 20 hours in both jobs and I never exceed 40 hours. Both businesses know that I work two jobs, and my tax code at my first job is 1257L, and at my second job, which I started later, my tax code is BR.
However, there is one thing that I'm curious about and want to be sure of because I don't want to have problems with the visa later on. As far as I know, payments are made on monthly working hours. And if in the future I am asked to prove that I do not exceed 20 hours per week during the academic calendar and 40 hours during the holidays, what should I do? Should I get a letter from the workplace or do I have documents that I need to keep just in case? Or should my workplace take action on this? I would be very grateful if you could help me with this topic.