There's only 5 people Ichigo used honorifics with

In the Japanese dub, when addressing someone, you usually address them with their last name, followed by an honorific unless they're a relative or a friend. Examples of honorifics are San, Kun, Dono, Sama etc.

Ichigo is a unique character in bleach in the fact that he's the only character in the show that refuses to use honorifics with anyone regardless of age or rank, including humans, soul reapers, hollows, Quincy and arancars. There's only 5 exceptions who Ichigo has always used their last name, followed by an honorific with. These 5 are urahara, tessai, yorouichi, Yamamoto, and rangiku. 3 of them are probably because they are his teachers for a brief moment.

Urahara and tessai trained him for 10 days and yorouichi trained him for 2 days and neither of them have any official affiliation with the soul society. The other 2 are members of the gotei 13. I can understand him calling Yamamoto with an honorific but I wonder why he also made an exception for rangiku, considering he didn't know about her connection with his father yet at the time, and he didn't know that his father was a soul reaper yet. Also he still refused to call toshiro by any honorific even though he calls his lieutenant by an honorific.

Just a little observation I've made