ARN full form
In GST, ARN stands for Application Reference Number. The GST portal generates it automatically when an application is submitted and verified (by DSC or OTP). It is your acknowledgement that the application has been filed, and the number you quote to track it.
The portal sends the ARN by email and SMS within minutes of submission.
ARN format: what the 15 characters mean
Take this illustrative ARN for a registration application from Bihar in September 2026: AA100926000123X
| Characters | Example | Meaning |
|---|---|---|
1–2 | AA | Fixed prefix used by the GST system |
3–4 | 10 | State code (10 = Bihar) |
5–8 | 0926 | Month and year the application was filed (MMYY) |
9–14 | 000123 | System-generated serial number |
15 | X | Check character |
When does the GST portal issue an ARN?
- New registration (REG-01). Use it to track the GST application status.
- Amendment of registration details, such as an address or partner change.
- Cancellation of registration, and revocation of a cancellation.
- Refund applications (RFD-01).
- Filing of returns: the acknowledgement for a filed return also carries an ARN.
ARN vs TRN vs GSTIN
| TRN | ARN | GSTIN | |
|---|---|---|---|
Full form | Temporary Reference Number | Application Reference Number | GST Identification Number |
When you get it | After Part A of registration | After submitting an application | After registration is approved |
Used for | Logging in to finish the application (valid 15 days) | Tracking that application | Your permanent GST number, on every invoice |
Using your ARN
- Registration: enter the ARN under Services → Registration → Track Application Status to follow the officer's decision.
- Refunds: track a refund application with its ARN under Services → Refunds → Track Application Status. The status shows whether it has been acknowledged, processed or paid.
- Queries from the department: notices about an application quote its ARN. Keep the acknowledgement email until the matter is closed.
Common ARN problems
- No ARN received. Check your spam folder first. If it isn't there, the application probably was never submitted: it only goes through after the final DSC or EVC verification. Log in with your TRN and check whether the application is still saved as a draft.
- "Invalid ARN" when tracking. Check for mix-ups between the letter O and zero, or I and 1, and that all 15 characters were entered.
- Two ARNs for one business. Each application has its own ARN. A later amendment or refund doesn't replace the original registration ARN, so track each one separately.
Not the same as an AMFI ARN
In mutual funds, "ARN" means something else: the AMFI Registration Number held by mutual fund distributors. If you saw ARN on a mutual fund statement, it identifies the distributor, not a GST application.
Applying for GST and want it done right first time? See TaxQue's GST registration service, or our step-by-step guide to applying.
