1. Meaning of UIN :- UIN stand for Unique Identification Number , is a special class of GST Registration for foreign diplomatic missions and embassies which are not liable to taxes in the Indian territory. What is UIN in GST? The Unique Identification Number (UIN) is a special identifier issued under the GST regime for specific entities that are not liable to pay tax in India but are involved in taxable supplies. It is a 15-digit alphanumeric code that is unique to each entity and helps distinguish them from regular taxpayers. Purpose of UIN: The primary purpose of assigning UINs is to facilitate the identification of entities that have a tax-exempt status but are still engaged in taxable ... UIN, or Unique Identity Number, which replaces the usual GSTIN (Goods and Services Tax Identification Number). It is a number provided to a few specified individuals as a unique registration number to use for their taxation process. GSTIN/UIN is a 15-digit number issued to businesses registered under the Goods and Services Tax (GST) in India. Learn how to verify GSTIN/UIN number online, its format, uses, and FAQs.