Most AO code confusion comes down to one thing people assume but should not: that the code for your PAN and the code for your TAN are the same. They are not. Once you sort that out, almost every other question about AO codes gets easier. Here are the ones people actually ask, answered plainly.
The basics
What is an AO code?
AO stands for Assessing Officer. The AO code points to the officer whose jurisdiction your record falls under. It is asked for when you apply for a PAN or a TAN, and it decides which officer assesses your returns later. One short code, but it is the link between your tax identity and a specific office.
What is it made of?
Four parts, every time: Area Code, AO Type, Range Code, and AO Number. The Area Code is three letters for the region. The AO Type is the assessee category. The Range Code and AO Number narrow it down to the exact officer. This structure is identical for both PAN and TAN, which is part of why people mix them up.
Is the AO code mandatory?
Yes, for both PAN and TAN applications. The form will not go through without it, and choosing the right one is the applicant's responsibility, not the portal's.
PAN, TAN, ITR: where they differ
Are PAN and TAN AO codes the same?
No. This is the single most useful thing to know. PAN and TAN have separate AO code searches and separate official lists. A code you found for your PAN is not automatically valid for your TAN. Use the right search for the right document.
| Document | What it is for | Official AO code search |
|---|---|---|
| PAN | Identifies a taxpayer (individual or entity) | Protean PAN AO code page |
| TAN | Identifies an entity that deducts or collects tax at source (TDS/TCS) | Protean TAN AO code page |
Where does ITR fit in?
ITR is not a separate AO code. It is the return your assigned officer assesses. The AO tied to your PAN is the one who reviews what you file, and if that officer spots a discrepancy in your return, they are the authority who can ask you to explain it. So the code you pick at PAN stage quietly decides who you deal with at ITR stage.
PAN AO code questions
What are the four AO categories for PAN?
When you apply, you are sorted into one of these:
| Category | Who it covers |
|---|---|
| International Taxation | Foreign nationals or companies not incorporated in India |
| Non-International Taxation (Mumbai Region) | Individuals living in Mumbai and companies registered in Mumbai |
| Non-International Taxation (Outside Mumbai) | Everyone else in India outside Mumbai |
| Defence Personnel | Indian Army and Indian Air Force members, with separate codes for each |
Mumbai getting its own category trips up a lot of applicants. If you are in Mumbai, you want the Mumbai Region option, not Outside Mumbai.
Ward or Circle: what is the difference?
The AO Type letter tells you. W (Ward) is generally for salaried individuals and lower income brackets. C (Circle) is generally for companies, firms, HUFs, and higher income cases. For most ordinary salaried applicants, a Ward code is the usual fit. The deciding factor is your income and entity type, not where you live.
Salaried or self-employed: which address sets my code?
If you are salaried, your jurisdiction usually follows your office location. If your income is from business or you are self-employed, it usually follows your residential address. People who recently changed jobs or moved house are the ones who most often end up in the wrong ward.
TAN AO code questions
I am applying for a TAN and do not know my Ward or Circle. What do I enter?
You are allowed to use the default AO code for the city where you file or intend to file your TDS return. On the search list, the default record for each city is the highlighted one. Some larger cities have more than one default depending on PIN code, region, or assessee type, so pick the one matching your location.
How do I search a TAN AO code?
Go to the Protean TAN AO code page, choose the AO code category for TAN, and it gives you the list (the current TAN AO Codes file version at the time of writing is 4.9). Filter for your city or location, then copy the Area Code, AO Type, Range Code, and AO Number into your TAN application (Form 49B).
Why does TAN even need an AO code if I already have one for PAN?
Because TAN is a different registration with a different purpose. PAN identifies you as a taxpayer. TAN identifies you as a deductor responsible for TDS or TCS, and it carries penalties if you are required to have one and do not. Quoting an incorrect or borrowed code does not serve you here. The deductor's jurisdiction is its own thing.
Finding and changing your AO code
I already have a PAN. How do I find my current AO?
Do not bother with the application search lists. Use Know Your AO on the Income Tax e-filing portal. Enter your PAN, verify with OTP, and it returns your current officer's name, jurisdiction, and contact details. This is the live answer, which matters because your AO can change over time even though your PAN stays the same.
And for TAN?
There is a separate Know Your TAN AO option on the Income Tax portal under Quick Links. You can search using your name or your TAN. Same idea, different document.
Can my AO code change?
Yes. A change in your residential address or business location can move you to a different jurisdiction. Your PAN or TAN number itself does not change, only the officer assigned to it. If you need the jurisdiction formally shifted, the route is an application to the new AO, and the change takes effect once the Commissioner approves it.
Which sites should I trust for this?
Only the official ones. Use the Protean (formerly NSDL) TIN portal for application-stage searches and the Income Tax e-filing portal for existing records. Third-party sites republish AO code lists, but those copies drift out of date and are not authorised. The department's own note is direct: the details shown are as received from the Income Tax Department, and if you are stuck you should contact your local Income Tax office or call the Aaykar Sampark Kendra on 0124-2438000.
Quick reference, official links:
- PAN AO code search: tinpan.proteantech.in/services/pan/pan-aocode.html
- TAN AO code search: tinpan.proteantech.in/services/tan/tan-ao-code.html
- Know Your AO / Know Your TAN AO: Income Tax e-filing portal (incometax.gov.in), under Quick Links
This data is verified from the official Protean (NSDL) TIN portal (PAN and TAN AO code pages at tinpan.proteantech.in) and the TIN-NSDL AO Code search, corroborated against TaxGuru, BankBazaar, and CAclubindia references confirming that PAN and TAN AO codes are maintained separately. Last verified May 2026. AO jurisdictions are restructured periodically by the Income Tax Department, so confirm your exact code on the official portal before submitting any application.
