An ISIN Checker for When a Mutual Fund Lookup Fails. And Why One Fund Carries Ten Identifiers.
Published: August 6, 2026
If you are calling the MFPro API, or working off a statement or a spreadsheet, and an ISIN comes back with an error, there is now a small checker at isin.tigzig.com that tells you whether the ISIN itself is wrong or the data is simply not there.
Malformed ISINs turn up often, and when one is wrong it is almost always a copy-and-paste accident rather than anything exotic, a character dropped in the middle or a digit changed at the end. Paste it in and the tool tells you whether it passes the ISO 6166 check digit, and when it does not, it says what is wrong. Where a character has been dropped it will often suggest what the ISIN was meant to be.
For Indian mutual funds it goes further and gives the fund name, the AMFI scheme code and the reinvestment ISIN where there is one, because someone working from a statement usually needs the other identifiers as well. You can paste a whole list and check them together, or type a fund name and get the ISIN back.
How many identifiers does a single mutual fund carry?
Take Axis ELSS Tax Saver Fund. It is one fund in four variants, because there is a Direct plan and a Regular plan, and each has a Growth option and an IDCW option. AMFI gives all four a separate scheme code and a separate NAV.
Then the ISINs. The two Growth variants have one ISIN each. The two IDCW variants have two each, one for the payout option and one for the reinvestment option, because a payout and a reinvestment are different instruments.
Direct Growth, 120503, INF846K01EW2
Direct IDCW, 120502, INF846K01EX0 and INF846K01EY8
Regular Growth, 112323, INF846K01131
Regular IDCW, 112322, INF846K01149 and INF846K01156
Four scheme codes and six ISINs, ten identifiers for what most people would call one fund.
So when someone reads an ISIN off a statement and cannot find the fund, it is often not a wrong ISIN at all, it is the reinvestment one, or the Regular one where they were looking at Direct. The checker at isin.tigzig.com returns the fund name, the scheme code and the reinvestment ISIN together, so you can see which of the ten you are holding.
A few things that come up once you start looking at ISINs
Some IDCW schemes have no payout ISIN at all, only the reinvestment one. Parag Parikh Flexi Cap Direct IDCW is one, scheme code 153964, where the payout field is empty and the only identifier is INF879O01308. So an empty ISIN column does not mean the fund has no identifier, and a lookup that reads only the primary field will report a live fund as missing.
SIF identifiers are a different case. A SIF ISIN is perfectly valid and still returns nothing from any mutual fund source, because AMFI's mutual fund feed carries no SIF schemes at all. That data sits separately for now at sif.tigzig.com, and I plan to fold it into the mutual fund pipeline once it has run clean for a while.
Names move, identifiers do not. A fair number of schemes were renamed in the SEBI recategorisation this year.
Quick links
- MFPro, the mutual fund app the data comes from: tigzig.com/mfpro
- The data API, for humans: api.tigzig.com/mf/v1/docs
- The data API, for agents: api.tigzig.com/mf/v1/openapi.json