A business visa (M visa) is issued to those who intend to go to China for commercial and trade activities. The business visa can be issued for single-entry, double-entry or multiple-entry. The validity period of the China M visa is three months in most cases, while the allowed duration of stay is usually 30 days and can be longer depending on applicants' personal cases. Citizens of Canada, Argentina, and the US can even get up to 10 years. China M or F visa is used to confuse many foreign visitors. From 2013, the original F is divided into M and F. The former is for business and trade, while today’s China F visa applies to noncommercial sci-tech and culture exchanges. The duration of stay (each visit) for each visa class is normally 30-60 days based on the particular Chinese Consulate. Original and photocopy of the business registration certificate and tax clearance or IRS are required during the visa application. You are also required to provide an invitation letter issued by a registered Chinese company or organization (for example, a trade fair). You could stay in China with a Business Visa for up to 120 days. It is illegal to work in China with a Business Visa. If you want to legally work in China, you need a Work Visa. China's business visa fees are the same as that of tourist visas. The applicant’s nationality and the number of entries make a difference. Generally, China's multiple-entry business visa costs more. In countries where there are CVASC, you need to pay both the Chinese M visa fee and the service fee to the center. It is possible to extend the M visa, but this must be done at least seven days before the original visa expires. Usually it costs 168 yuan for a single extension.