indian_form_validators 1.0.0

A comprehensive, zero-dependency Dart package for validating Indian financial and identity form fields — PAN, Aadhaar, IFSC, GST, UPI, mobile numbers, and pincodes. Includes Verhoeff checksum for Aadhaar.

indian_form_validators

A comprehensive, zero-dependency Dart package for validating Indian financial and identity form fields.

Works as drop-in validators for Flutter TextFormField widgets.

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Features

Field	Validator	Extras
PAN Card	✅ Format validation	Taxpayer type lookup
Aadhaar Number	✅ Verhoeff checksum	Format / Mask utilities
Mobile Number	✅ TRAI digit rules	Prefix normalization (+91, 0)
GST Number	✅ Format + state code	State lookup / PAN extraction
IFSC Code	✅ Format validation	Bank name / branch code
Pincode	✅ 6-digit zone rules	Postal zone lookup
UPI / VPA	✅ VPA format	Handle recognition

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Installation

dependencies:
  indian_form_validators: ^1.0.0

Then run:

flutter pub get

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Usage

Option 1 — Single import (recommended)

import 'package:indian_form_validators/indian_form_validators.dart';

TextFormField(
  decoration: InputDecoration(labelText: 'PAN Number'),
  validator: IndianValidators.pan,
)

TextFormField(
  decoration: InputDecoration(labelText: 'Aadhaar Number'),
  validator: IndianValidators.aadhaar,
)

TextFormField(
  decoration: InputDecoration(labelText: 'Mobile Number'),
  validator: IndianValidators.mobile,
)

Option 2 — Individual classes

import 'package:indian_form_validators/indian_form_validators.dart';

// Returns null if valid, error string if invalid
final error = PanValidator.validate('ABCDE1234F'); // null

// Boolean check
final isValid = PanValidator.isValid('ABCDE1234F'); // true

// Utility
final type = PanValidator.getTaxpayerType('AABCP1234D'); // "Individual (Person)"

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Validators in Detail

PAN Card

PanValidator.validate('ABCDE1234F');        // null ✅
PanValidator.validate('abcde1234f');        // null ✅ (normalized)
PanValidator.validate('INVALID');           // "Invalid PAN format..."

PanValidator.getTaxpayerType('AABCP1234D'); // "Individual (Person)"
PanValidator.getTaxpayerType('AABCC1234D'); // "Company"

Format: AAAAA9999A — 5 letters, 4 digits, 1 letter

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Aadhaar Number

AadhaarValidator.validate('499118665246');        // null ✅
AadhaarValidator.validate('4991 1866 5246');      // null ✅ (spaces stripped)
AadhaarValidator.validate('012345678901');        // "Aadhaar cannot start with 0 or 1"
AadhaarValidator.validate('499118665247');        // "Invalid Aadhaar (checksum failed)"

AadhaarValidator.format('499118665246');  // "4991 1866 5246"
AadhaarValidator.mask('499118665246');    // "XXXX XXXX 5246"

Uses the Verhoeff algorithm for checksum validation — the same algorithm UIDAI uses.

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Indian Mobile Number

MobileValidator.validate('9876543210');      // null ✅
MobileValidator.validate('[phone]');   // null ✅
MobileValidator.validate('09876543210');     // null ✅
MobileValidator.validate('5876543210');      // "Must start with 6, 7, 8, or 9"

MobileValidator.normalize('[phone]'); // "9876543210"

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GST Number

GstValidator.validate('27AAPFU0939F1ZV'); // null ✅
GstValidator.getState('27AAPFU0939F1ZV'); // "Maharashtra"
GstValidator.extractPan('27AAPFU0939F1ZV'); // "AAPFU0939F"

Format: SS AAAAA 9999 A E Z C — 2-digit state code + PAN + entity + Z + checksum

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IFSC Code

IfscValidator.validate('HDFC0001234');    // null ✅
IfscValidator.getBankName('HDFC0001234'); // "HDFC Bank"
IfscValidator.getBranchCode('HDFC0001234'); // "001234"

Format: ABCD0123456 — 4-letter bank code, 0, 6-char branch code

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Pincode

PincodeValidator.validate('400001');    // null ✅ (Mumbai)
PincodeValidator.getZone('400001');     // "Maharashtra / MP / Chhattisgarh / Goa"
PincodeValidator.validate('012345');    // "Cannot start with 0"

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UPI / VPA

UpiValidator.validate('viraj@okicici');          // null ✅
UpiValidator.validate('9876543210@paytm');        // null ✅
UpiValidator.getHandle('viraj@okicici');          // "okicici"
UpiValidator.isKnownHandle('viraj@paytm');        // true

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All Supported Validators via Facade

IndianValidators.pan(value)
IndianValidators.aadhaar(value)
IndianValidators.mobile(value)
IndianValidators.gst(value)
IndianValidators.ifsc(value)
IndianValidators.pincode(value)
IndianValidators.upi(value)

// Boolean helpers
IndianValidators.isValidPan(value)
IndianValidators.isValidAadhaar(value)
IndianValidators.isValidMobile(value)
IndianValidators.isValidGst(value)
IndianValidators.isValidIfsc(value)
IndianValidators.isValidPincode(value)
IndianValidators.isValidUpi(value)

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Why This Package?

Building Indian fintech apps means constantly writing the same regex patterns and rules. This package gives you:

• Zero dependencies — no bloat, no conflicts
• Null-safe — fully sound Dart null safety
• Flutter-ready — validators return String? so they plug directly into TextFormField
• Utility extras — not just validation, but formatting, masking, and data extraction
• Tested — comprehensive unit tests for all validators

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Contributing

Issues and PRs are welcome! Please open an issue before submitting large changes.

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License

BSD 3-Clause — see LICENSE