A regular expression that matches a valid EIN (Employer Identification Number) number.
The Employer Identification Number (EIN) is a unique serial number assigned by the IRS to business entities operating in the US. The EIN contains nine digits divided into three groups: “two-digits, dash, seven-digits”. It is separate from the Social Security Number, which is used by individuals.
^\d{2}\-?\d{7}$
Matches:
- 15-4321671
- 154321671
Non-matches:
- 154-321671
- 12-4321672
- ab-1234567