Hey @julia n​ if the number is saved as custom attribute that means you can search users with that attribute value, and then check conversations around the time you know this conversation was conducted. I understand this can be a bit hard if the user had many conversations. But anyhow, custom attribute can not be overwritten with custom bot (it can be set only once as far as I know), so if your users are making multiple requests of that type, you should stay away from using custom attributes.

Or you just let them type in the number in composer and then it will be searchable (and perhaps an agent manually creates a tag with that number).