It depends on your subscription plan!
Free trial accounts can monitor up to 10 keywords at a time. With a Individual plan, you can monitor 3 keywords, Team comes with 7 keywords, Pro with 12 keywords and Enterprise users can monitor up to 25 keywords.
If you need a custom plan - we can make that happen, please reach out to our Customer Success Team :)
If you are logged into Brand24, you can check your current limits here.