Can I have multiple API keys in one account?

Yes, it's possible that they have multiple API keys for the same subscription. In the Customer Portal, navigate to Subscriptions > APIKEYS > CREATE APIKEY

The multiple API keys can be limited via the configuration of the specific API key, for example the specific API key newly created cannot overage or limit the specific API key to X number of requests to avoid causing issues for other keys. 

Increased security is one of the main benefits of having numerous API keys. Each key acts as an access point and particular identifier. Users can compartmentalize their access by making unique keys, which lowers the likelihood that a security breach will have a negative effect. The remaining keys are unaffected if one key is hacked, protecting sensitive information and reducing risks.