Additional place of business

A Delhi-registered GST dealer owns property in Haryana that is let out to another GST-registered person in Haryana. The dealer issued a bill from Delhi using their Delhi GST number and charged IGST. The query is whether the dealer needs Haryana GST registration and should charge CGST/SGST, or if charging IGST is correct. The consensus is that for billing outside the state, even with immovable property, IGST should be charged using the Delhi GST number.