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About this tool
Build a card of official numbers you trust enough to call back on, with Indian number-format checks and a source trust rating.
A callback card is the short list of numbers you trust enough to dial after hanging up on a caller who claims to be your bank, a delivery company or the police. This builder checks each number against India's numbering plan — 10-digit mobiles starting 6 to 9, landlines with an STD code, 1800 toll-free lines and 1xxx service short codes — and then rates where you got it from, because that is what actually decides trust. Numbers taken from your own card, statement, a signed-in app or a branch qualify; numbers from search results, sponsored ads, SMS forwards or the caller themselves do not, and are kept off the card with the reason shown.
Open Callback Verification Number Builder on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
A valid-looking number from a search ad is still rejected, with the reason spelled out.
Mobile, landline, toll-free and short-code formats are validated separately, with the trunk 0 and +91 handled.
The card copies out as plain text you can print, stick on the fridge, or save in a notes app.
It is a number you obtained yourself from a source the organisation gave you — the back of your card, your statement, the signed-in app, or a branch — and which you dial after ending a suspicious call. Using it defeats caller-ID spoofing, because you control which line you connect to rather than trusting the one that rang you.
Fake helpline listings and sponsored ads are one of the most common ways people are handed a scam number, and they often rank above the real one. Type the organisation's own domain into the address bar or open its app instead, and read the number from there.
Mobiles are exactly 10 digits and start with 6, 7, 8 or 9, written internationally as +91 followed by those 10 digits. Landlines are also 10 digits in total once the trunk 0 is removed (STD code plus subscriber number), toll-free lines start 1800, and service numbers such as 112, 139, 1915 and 1930 are short codes on level 1.
Call 1930, the national cyber-crime financial fraud helpline, and file a complaint at cybercrime.gov.in as soon as possible, then inform your bank in writing. Reporting within the first hours gives the best chance of the beneficiary account being frozen; this is general information rather than legal advice.