rtn

Validates a US RTN (Routing Transit Number) used to identify financial institutions.

Options

Option	Type	Default	Description
message	string	locale default	Custom error message

Playground

Valid values

Value	Notes
"021000021"	JPMorgan Chase routing number
"011000138"	Bank of America routing number

Invalid values

Value	Reason
"021000022"	Fails weighted checksum
"12345678"	Only 8 digits instead of 9

Notes

• Empty string ("") always returns valid: true. Combine with notEmpty to require a value.
• RTN is exactly 9 digits. Validated using a weighted checksum (mod 10).