To verify a trade company in Qinhuangdao, China, you would typically follow these steps:

1. **Legal Document**:
– Look for the company’s registration certificate, also known as a business license. This document is issued by local administrative departments and confirms the legal existence of the company.

2. **Company Information Online**:
– Visit official government websites such as the Qinhuangdao City Government Portal. Search for ‘company registration’ or similar keywords to find a list of registered companies.

3. **Contact the Company Directly**:
– If you are unable to find information online, contact the trade company directly using their provided contact details (usually found on their website).

Remember that verifying a company’s legal status is an ongoing process and may require periodic updates or checks.