PAN, GSTIN, TAN, Aadhaar & IFSC: ID Formats Explained (2026)

Indian financial IDs look random, but each one has a fixed grammar — position by position, the characters reveal the issuer, the holder type and even a person’s surname. This decoder breaks down PAN, TAN, GSTIN, Aadhaar, IEC, IFSC, CIN, the Udyam number, DIN and the LUT ARN with structure tables, plus one verification tip for each, so you can confirm any ID in minutes.

PAN — Permanent Account Number

The fourth character is the fastest tell: P individual, C company, H HUF, F firm or LLP, A association of persons, T trust — with further codes for bodies of individuals, local authorities and government. So a PAN like ABCPK1234F belongs to an individual whose name starts with F.

Verify it: run the “Verify Your PAN” facility on the income tax e-filing portal — it confirms the PAN’s status against the department’s records instantly.

TAN — Tax Deduction Account Number

TAN follows the pattern AAAA99999A — four letters, five digits, one letter. The opening letters identify the jurisdiction where the deductor is registered, the fourth letter echoes the deductor’s name, the digits are sequential and the last character is an alphabetic check.

Every employer, bank or company deducting TDS must hold a TAN and quote it in certificates and returns — you can see your employer’s TAN in Form 16 (Form 130 from tax year 2026-27) and Form 26AS (Form 168 from tax year 2026-27). Verify it: use the “Know Your TAN” search on the Protean (formerly NSDL) TIN portal to confirm the deductor’s registered name.

GSTIN — Goods and Services Tax Identification Number

Because positions 3–12 are the PAN, one PAN can hold several GSTINs across states, distinguished only by the entity digit. Verify it: use the GST number verification tool or “Search Taxpayer” on gst.gov.in to confirm the legal name, trade name and registration status.

Aadhaar and VID

Aadhaar is a 12-digit number with no hidden meaning — the first digit is simply not 0 or 1, and the rest carry no code you can read. The VID (Virtual ID) is a 16-digit number you can generate and regenerate against your Aadhaar, letting you authenticate without sharing the base number.

Verify it: use “Check Aadhaar Validity” on the myAadhaar portal (uidai.gov.in) — it confirms whether a 12-digit number has been issued, without exposing personal details.

IEC — Import Export Code

The IEC is a 10-character code issued by DGFT to anyone importing or exporting, and it is linked to the entity’s PAN — one PAN carries one IEC. IEC holders confirm or update their particulars each year between April and June, even when nothing has changed, or the code risks deactivation.

Verify it: the “View IEC / IEC Status” facility on the DGFT portal shows the IEC’s current status against the entity name.

IFSC — Indian Financial System Code

Bank mergers retire old IFSCs, so an IFSC copied from an old cheque book can be dead even though the account is alive. Verify it: check the code against the RBI’s published list or use the IFSC code search tool before adding a beneficiary.

CIN — Corporate Identity Number

At 21 characters, the CIN encodes the company’s entire registration story, and it stays constant for the company’s life. Verify it: use “View Company Master Data” on the MCA portal to match the CIN with the company’s legal name and status.

Udyam Registration Number

The Udyam number follows the pattern UDYAM-<state code>-<district code>-<serial> — for example, UDYAM-MH-01-0012345 in an illustrative form. It is issued free to micro, small and medium enterprises and is anchored to the enterprise’s PAN and the owner’s Aadhaar.

Verify it: the “Verify Udyam Registration Number” facility on udyamregistration.gov.in confirms a valid registration — useful because lookalike paid websites exist.

DIN — Director Identification Number

The DIN is an 8-digit unique number allotted to an individual director, valid for life and the same across every company the person directs. Companies quote it in filings, so it travels through MCA records. Verify it: use “View Signatory Details” on the MCA portal to confirm a director’s DIN and the companies linked to it — a quick check before signing agreements with unfamiliar counterparties.

LUT ARN — Letter of Undertaking acknowledgment

When you file the LUT (Form GST RFD-11) on the GST portal, the system generates an Application Reference Number (ARN) as proof of filing. Exporters quote this ARN to banks and buyers as evidence of a valid LUT for the financial year, permitting zero-tax supply without IGST payment. Verify it: track any ARN under Services, then User Services, then Track Application Status on gst.gov.in.

Reading IDs like a professional

• PAN sits inside GSTIN and IEC — decode those first ten characters and two more IDs unlock.
• The fifth character of PAN and the fourth of TAN both echo a name, which makes obvious fakes easy to spot.
• Geography repeats: the GSTIN’s opening digits and the CIN’s state letters both name the state, and local postal context can be checked with a PIN code search.
• When a document matters — a property deal, a big invoice — verify the ID on the issuing portal rather than trusting formatting alone.

Key takeaways

• PAN (10-character), TAN (AAAA99999A) and GSTIN (15-character) share the alphabet-plus-check digit grammar — learn one and the rest follow.
• GSTIN = state code + PAN + entity number + Z + checksum; the PAN inside tells you the holder type.
• Aadhaar is 12 digits with no embedded meaning; the 16-digit VID is its shareable stand-in.
• IFSC is four bank letters, a permanent 0, and six branch characters — verify after any bank merger.
• Every ID here has an official verification facility; one check beats an afternoon of doubt.

Frequently asked questions

Does the fourth character of PAN prove a PAN is genuine?

It only reveals the holder type, so a mismatch with the claimed entity is a red flag but a match is not proof. Always confirm on the e-filing portal’s verification facility.

Why is the fifth character of an IFSC always 0?

The fifth position is reserved for future use by the RBI’s numbering scheme. Only the last six characters change as you move between branches.

Is there a checksum in Aadhaar?

Aadhaar does not publish a public checksum algorithm you can run yourself. Validation happens against UIDAI records through the official validity check.

How do I find a company’s CIN?

Search the company name in MCA’s master data facility — the CIN appears with the registration date, state and status. The first character even tells you whether it is listed.

What is the difference between DIN and PAN?

PAN is a person’s fiscal identity, while DIN identifies the same person in the role of a company director. One person holds one of each, for life.

Disclaimer: Tax laws change frequently. Verify current rates and deadlines on the official portals (incometax.gov.in, gst.gov.in) or consult a qualified professional before acting.