Visiting a supplier at his office is not exactly the same as attending a high fashion business meeting but there are dress code standards that should be observed.
It is not appropriate to wear your favorite T-shirt from your last holiday in Thailand when you visit your suppliers or any factory.
Chinese people are not particularly picky when it comes to clothing but keep in mind the impression you will make of yourself and your company.
Appropriate dress is a business suit or a light jacket with a collared shirt.
Years ago, air-conditioners at the Canton Fair were not very efficient. Wearing a suit felt like you were in a public sauna. Fortunately, that has changed and today you will find the exhibition halls in both Hong Kong as well Guangzhou comfortable.
You may even appreciate wearing a jacket because most Chinese consider Westerners to be cold loving and often set the air-conditioning to a lower temperature to please them. Siberia may be a much warmer place compared to that.
It is not necessary to wear a necktie when attending the Trade Fair but when visiting your suppliers’ offices and if you are invited to a business lunch (mostly linked together) or more likely a business dinner, a necktie is appropriate.
If your business trip takes place during the Trade Fair season (April & October) which is also the warm season, you will want to wear light clothes, especially when you are outside of the air-conditioned hotel rooms, suppliers’ showrooms, and exhibition centers.