Employment Visas
It is necessary to obtain the appropriate working visa to be able to work in Korea.  The process of giving the visas to the foreigners is under the touch control of the government. In some cases, teachers have been unable to obtain the appropriate visa.  

You also need to have visa outside Korea. If you came to the country with tourist visa and than was offered a job, you can then apply for a work visa at a Korean diplomatic or consular mission in a nearby country, such as Hong Kong or Japan, provided that a Confirmation of Visa Issuance number has been provided in advance by the person who employs you. Before traveling to the nearby country, be sure to confirm with the Korean mission there that they will process visa applications from foreign citizens. Though the procedure is very complicated it can be beneficial in the end.

It can take from 1 week up to 2 month to get the visa.  However, visa applications submitted to Korean missions in Japan (Tokyo, Osaka, and Fukuoka) are usually processed within two working days. But you must be ready to stay there as long as necessary to get the visa.

The required documents and visa regulations may change almost every year, you should contact the nearest Korean Embassy or consular mission if you are outside Korea, or a Korean immigration office within Korea, for confirmation of regulations and fees. If they have changed you must be aware of it.

When coming to Korea, you must register at a Korean immigration office and obtain a residence permit and a re- entry permit within 90 days of coming. All foreigners are required to possess a valid re-entry permit in order to be able to stay in Korea for a longer period of time. Immigration offices in Korea have the same documentation requirements as the needed for the visa obtaining, so you need to have a lot of copies of your main documents.

The majority of English speaking tutors and teachers are given an E-1 visa (professor at an educational institution higher than a junior college), an E-2 visa (conversation instructor) or an E-5 visa (professional employee with a public relations firm or corporation). Those who deal with diplomatic work can get the visa at the Ministry of Foreign Affairs. A permanent residency can be given to a person who is married to other Korean citizen; he may get a Spouse visa.

In of the saying of any Korean employers, you are not required to hand over your home passport to your employer for the when coming and staying in the country. Keep your passport not far from you all the time.

Required Forms
Before getting a resident permit or obtaining a visa (within 90 days of entry), you must submit the following documents to the relevant Korean government office:

- a sponsorship guarantee form;
- an employment contract valid for not less that 1 and no longer than 2 years;
- an employment certificate.

These documents are supplied by your employer and should be arranged one month in advance to allow for delays arising from mistakes and other mishaps. The government can ask also the following documents: 

    * a statement of purpose;
    * a CV;
    * your 4 bachelor degree copy and original;
    * your drivers license if any.

The government of Korea is carefully investigating every case of fake documents, university degrees and ESL certificates use. Punishment for using fake documents includes deportation and restrictions on re-entry for five years or more.

Changing Your Employer
If you want to change the employer, you need permission from Korean government, in principle; you should have a new visa and a new sponsor. To change the present employer you need to get permission from the current one and later consider the matter of finding the new. The nearest immigration office may help you in this.

If you want to go to another employer without the release from the previous one, you must leave the country within 14 days after your resignation. You won’t get new job permit without leave from the previous one.  However, after leaving the country, you can return to Korea as a tourist while awaiting the expiry of your old contract, although you are not allowed to work in the interim. 
Legal Problems
Some teachers had problems with government because either they have got employed while having only tourist visa or they took private classes without the necessary permission. Violation of Korean immigration laws can result in severe penalties, including sending to the prison, fines of up to 50,000 won for each day of overstay, or deportation with a ban on re-entry, usually for up to two years. So you should learn some local laws and do not make crimes. Your home government offices cannot assist you in any way if you violate Korean laws, other than to provide you with a list of lawyers. But don’t come to this point.