Joint inbox for sms

We have 2 offices and the txt messages come up for both offices, this is confusing for each office. We need to work out what office the patient is for before replying. If one office opens the inbox the red dot goes away so the other office does not know there is something for them to read. The only way to counter this is to go into conversation and click unread. I would like to have the txt message inbox only open up for the office you on. EG Kew or  Melbourne. I have discussed this with someone already today. Can this be fixed via updated software?