Mexico CLABE Check Digit Validator

Validate Mexico CLABE eighteen-digit checksum with repeating 3/7/1 weights and per-product mod ten; exact digits preserve zeros, checksum agreement is not institution/account assignment or payment authorization.

Description

The standardized Mexican bank account key, CLABE, uses eighteen digits with a final check digit.

The standardized Mexican bank account key, CLABE, uses eighteen digits with a final check digit. A valid checksum is a structural consistency check rather than account verification.^{[1, 2]}

The returned values include Expected check digit, Check digit matches. The How section below explains the calculation, input rules and interpretation.

When to use Mexico CLABE Check Digit Validator

Use Mexico CLABE Check Digit Validator when you need to evaluate the supplied records under the calculation and evidence rules below. No institution/account assignment or payment authorization is supplied.

Prepare observed financial records and verified caller terms. Use one currency for integer minor-unit money and preserve leading zeros in identifier text. One basis point is 0.01 percentage points. Resolve dates, local clocks, counting rules and evidence flags as specified.

How to use Mexico CLABE Check Digit Validator and understand its results

Prepare observed financial records and verified caller terms. Use one currency for integer minor-unit money and preserve leading zeros in identifier text. One basis point is 0.01 percentage points. Resolve dates, local clocks, counting rules and evidence flags as specified.
Enter clabeText using the field table and calculation rules, then run the tool.
Read expectedCheckDigit, checkDigitMatches. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
clabeText	Clabe text	string	Required

Enter exactly eighteen ASCII digits without whitespace or newline. Weight the first seventeen digits cyclically by 3,7,1, reduce each product modulo ten and compute the complementary check digit. Return expected digit text and match flag; checksum mismatch is a valid false result.

expected=(10−sum((digit_i×[3,7,1]_i) mod 10) mod 10) mod 10

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
expectedCheckDigit	Expected check digit	string
checkDigitMatches	Check digit matches	boolean

json

{
  "input": {
    "clabeText": "111111111111111115"
  },
  "output": {
    "expectedCheckDigit": "5",
    "checkDigitMatches": true
  }
}

Limitations and assumptions

No institution/account assignment or payment authorization is supplied.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Nigeria NUBAN Check Digit Validator: The legacy NUBAN checksum combines a three-digit bank code with nine account-body digits. Checksum agreement cannot establish that an account exists. For a complementary task, use MICR Line Routing Account Parser: Normalized MICR notation separates routing, account and check serial text. Explicit delimiters preserve leading zeros without guessing an OCR layout.

Further background: Frequently asked questions: CLABE structure.

References

Mexico CLABE Check Digit Validator — tool.io
Frequently asked questions: CLABE structure — Banco de México

Similar or alternative tools

Nigeria NUBAN Check Digit Validator
The legacy NUBAN checksum combines a three-digit bank code with nine account-body digits. Checksum agreement cannot establish that an account exists.
MICR Line Routing Account Parser
Normalized MICR notation separates routing, account and check serial text. Explicit delimiters preserve leading zeros without guessing an OCR layout.