Abbas Di Palma, Shaykh Abbas Di Palma holds a BA and an MA degree in Islamic Studies, and certifications from the Language Institute of Damascus University. He has also studied traditional Islamic sciences in... Answered 3 years ago

It is not permissible for a man to only have beard in his chin as it implies "shaving"  which is considered haram. As far as the trimming, the Muslim person should be considered as  "having beard" according to common view.

With prayers for your success.