There are two main types of tax credits in USA:
Non-refundable tax credits can lower the amount of tax you owe, but they won’t result in a refund if your balance is already zero. For instance, charitable donations can earn you a non-refundable credit.
Refundable tax credits not only reduce your tax liability but can also provide you with a refund, even if you don’t owe any taxes at all.
These credits can support a range of life expenses—from childcare and housing to healthcare and income support.
Tax filing requirements apply regardless of age. Whether you're 9 or 90, if you meet the income or criteria thresholds, the CRA expects you to file a return.
Students aren’t exempt either. For example, if a college student earned over $3,500 (after expenses) from a summer side business, they are required to file a tax return—even while enrolled in school. As a general rule, any working individual should begin filing as soon as they start earning.