With the second beta of iOS 18.2 that's available for developers today, Apple has further fleshed out the ChatGPT integration that's available with Siri. In the Settings app, there's now a section that shows the ChatGPT daily limit, and offers an option to upgrade to the paid ChatGPT Plus plan.
The beta includes an Advanced Capabilities section with a "Daily Limit" reading that shows up as "Under Limit" without a paid ChatGPT plan. Users have access to a small number of requests that use the most advanced ChatGPT capabilities, and requests are downgraded to a basic version of ChatGPT after that.
OpenAI has long restricted access to ChatGPT's most advanced feature set to a paid Plus plan, so accessing ChatGPT through Siri is subject to the same limitations.
There is an option to upgrade to ChatGPT Plus, which is priced at $19.99 per month. ChatGPT Plus provides 5x more messages on the newest version of ChatGPT, GPT-4o. It also allows for higher limits on photo and file uploads, image generation, and web browsing, as well as an option to converse with ChatGPT using advanced voice mode.