Two things are true at once and students usually only hear the first. Yes, you can work while you study in most destinations. No, that work will not fund your degree, and planning as though it will is how people end up in trouble.
Let us take the rules seriously first, because these are visa conditions, not guidelines.
What the limits look like
Canada is the clearest. You can work up to 24 hours per week off campus during your study terms, and full time during scheduled breaks. You need a social insurance number, and if you are eligible there is no fee to have the work condition added to your permit.
The UK sets your limit according to what you are studying and whether it is term time, and the permission you are granted is stated in your own visa decision. Degree-level students get more hours than those on lower-level courses. Do not rely on what a friend on a different course was allowed. Read your own conditions, because they are personal to your visa.
The UK also blocks certain activity outright regardless of hours. You cannot be self-employed, you cannot work as a professional sportsperson or sports coach, and you cannot claim public funds.
Australia caps hours over a fortnight rather than a week, which gives you more flexibility to work around a busy shift pattern, with the same principle of a hard ceiling during study periods.
The pattern across all of them: a capped number of hours while classes are running, more during official breaks, and the cap written into your visa.
Why breaching it is worse than it sounds
Students treat an extra few hours as a small thing. Immigration systems do not.
Working over your limit is a breach of your visa conditions. It can mean your permission to stay is cancelled, your studies end, and a future visa to that country becomes very hard to obtain. It can also affect a later application for post-study work or residency, because the breach stays on your record.
The employer usually faces nothing. You face everything.
Cash-in-hand work is the common route into this, and it carries the additional problem that you have no evidence of your own hours if anyone asks.
The arithmetic on tuition
Run the numbers before you leave, because the fantasy version has broken a lot of plans.
Take the legal hourly limit, multiply by a realistic wage for a student job in that city, subtract rent, food, transport and phone. What remains is your contribution, and in most destinations it covers part of your living costs and nothing else.
This is exactly why visa officers require you to show a full year of funds separately. They are not being difficult. They already know the arithmetic.
If your plan only works when you assume full-time earnings, the plan does not work, and an officer reading your file will see the same gap you are choosing not to look at.
Finding work once you are there
On-campus jobs are usually the best first move. Library, cafeteria, lab assistant, student services. They understand your hour limits, the pay is legitimate, and the hours fit around teaching.
Get your tax or insurance number sorted immediately on arrival, because most legitimate employers cannot put you on the payroll without it and this is the single most common reason students sit idle for their first two months.
Keep your own record of hours worked each week, especially if you have more than one job. The responsibility for staying within the cap is yours, and no employer is tracking your total across two workplaces.
What to do before you fly
Read the work conditions on your own visa grant, not a summary. Budget on the assumption that you find work in month three rather than week one, because that is how it usually goes. Carry enough to cover the first couple of months without earnings.
Work rules do get revised, and Canada's hour limit in particular has moved in recent years. Message us on WhatsApp before you rely on a number for budgeting and we will confirm the current rule for your country and course level.