What part-time jobs are suitable for PhD students?
Two obvious answers are:
- Marking (grading). Ask your supervisor if they have coursework that needs to be marked (for a price).
- Tutoring. Put a note up in your departmental office offering to tutor undergraduates. If you're doing a more mathematical degree, you could tutor undergraduates from other disciplines. For example, helping out with some statistics coursework.
I know of a few graduate students who successfully made money doing consulting in their line of work. Most of these were engineering students, where the knowledge gained during graduate school is easily transferable, but I've seen others as well.
If you're interested in this, talk to as many people as you can and network, network, network. It can be a fun side project with the potential to become a full-time job if you're interested.
Another very useful skill that some graduate students may be able to do is grant writing. While you may not realize it, this skill is necessary in many, many industries, and if you're good at writing, you can make earn some good income contracting out your skills.
It would depend on whether you are an international student or a domestic student. I am guessing, if you are an international student, you will have to work with your international office to work more than your allowed quota of hours citing extenuating circumstances.
For instance, as a PHD candidate from India in the USA, I know that I get a stipend that counts as 20 hours of work per week. If I were to have, God forbid, extenuating circumstances and needed more money to support my cause, I'd have to work with the international office who in turn would work it out with the INS/ICE in the US so that I stay "in status" as a full time student whilst working for more than my quota of hours.
Obviously, my answer is for international students in the US. If you are a domestic student, some of the answers provided here would actually help!
Good luck!