I'm coming to Seoul to study at 어학당 (language school) on a D-4 visa?

On a D-4 visa, you need to have completed at least 6 months of study and reached TOPIK level 2 or higher before you can apply for a part-time work permit (시간제취업허가). To apply, visit your local immigration office with your passport, ARC, enrollment certificate from your school, TOPIK score report, attendance record showing at least 90% attendance, and a letter from your employer.

The most common jobs for D-4 holders are working at convenience stores, cafes, restaurants, and doing private language tutoring. You are limited to 20 hours per week during the semester and more during vacations. The pay is usually minimum wage which is currently around 10,030 won per hour. Your school can help with the application process and some even have job boards connecting students with part-time opportunities. One important thing to know is that you must get the work permit approved before you start working. Working without the permit can lead to fines or even visa cancellation. Also make sure any job you take falls within the allowed categories for your visa type.