Address

Because where a thing is sent, where a bill is sent, and where an entity is legally registered are three different questions with three different answers.

The address is deceptively load-bearing in India: it carries the state, the state determines place of supply, and place of supply determines whether a transaction attracts CGST+SGST or IGST. A data-entry field in most systems is a tax-determination input here, which is why it deserves validation rather than free text.

• A party may hold many addresses, and each has a purpose — billing, shipping, registered. One address serving all three is a coincidence, not a rule.
• In India the address carries the GSTIN and the state, which is why place of supply derives from it rather than from a company setting.
• Changing an address on a party must not retroactively alter documents already issued to the old one.

Addresses are treated as descriptive text because that is what they are everywhere else. Then the state is missing or wrong on a few hundred records, the tax applied was wrong, and the correction is a restatement rather than an edit.

• Bill-to and ship-to in different states, where place of supply follows a statutory rule rather than the delivery address.
• Customers with a registered office they never operate from — correct for invoices, wrong for deliveries.
• Addresses shared by group companies at one premises, where the same physical location has two GSTINs.
• Export addresses with no Indian state at all, which the tax logic must handle rather than default.