GST Applicability in case of 2 seperate business on proprietor

Nitesh (Ipcc both group) (60 Points)

02 August 2022  
If an Individual has 2 business :
1) IT services provider
2) Cleaning Services.

Cumulative Turnover of Both business combined is less than 15 lacs for PY. and similar for the Current year is expected.

Voluntary GST registration taken for Cleaning Services from April 22. GST charged and paid on the same.

However assessed has not charged GST on IT services bills considering that he's unregistered for IT services.

Is he required to issue GST bills for IT services too?

Is there any relief granted from GST for seperate business if turnover of all combined businesses is not in excess of specified limits?