GST Number Explained! Most people don’t realise it, but a single GST number can reveal a lot about any registered business in India - and the funny part is, it’s printed everywhere: bills, boards, websites, even shop entrances. A GSTIN is a 15-digit ID that becomes mandatory once a service business crosses ₹20 lakh in turnover or a product business crosses ₹40 lakh. But those 15 digits aren’t random, every part of that number tells a story: - The first two digits show the state code (like 07 for