To verify a trade company in Chengde, a city located in the northern part of China, you would typically follow these steps:

1. **合法性检查**:
– First, ensure that the company is legally registered. Check their business registration number (often called “营业执照号码”), which should be listed on public records.

2. **Online verification**:
– Visit official government websites for trade and industry in Chengde. These sites usually have a company search function where you can input the registration number to verify authenticity.

3. **Contacting the company**:
– If online verification is inconclusive, you may reach out directly to the company via phone or email. This way, you can confirm their official stance and address any concerns.

Remember that verifying a trade company’s authenticity is an ongoing process, as companies might change their registration details.