Are employees at AI companies allowed to use competing AI models?

I randomly had this thought the other day. How strict are AI companies about their employees using competing AI models?

For example, if you work at Google, are you actually free to use ChatGPT or Claude for work, or are employees expected to stick to Gemini?

And what about people working at OpenAI or Anthropic? Are they allowed to use competing models for work-related tasks?

I’m not really asking which model they prefer. I’m more curious about the actual company policies around this, especially when it comes to sensitive or proprietary work information.

Do these companies actively restrict employees from using competitors’ AI services, or is it more like “use whatever tool is approved and secure”?