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 dressing is a business suit or a light jacket with a collared shirt.
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 weight clothing, especially when you are outside of the air-conditioned hotel rooms, suppliers’ showrooms, and exhibition centers.
In Chinese culture, conservative suits and ties in subdued colors are the norm. Bright colors of any kind are considered inappropriate. Women should wear conservative suits or dresses; a blouse or any other kind of top should have a high neckline. Stick with subdued, neutral, colors such as beige and brown.