In guide it is not specifically mentioned about the format to be checked for the fields related to employer's identification number or social security number.
Can you please clarify what kind of format check should be done for these numbers across different transaction where "Employer's Identification number" is used and whether "000000000" is valid EIN or SSN number?
Additional information emailed on 9/10/20
In 837P Implementation Guide, segment REF-Billing Provider Tax Identification (2010AA), field REF01 is having two qualifiers EI and SY and the code definition states “The Employer’s Identification Number must be a string of exactly nine numbers and no separator”, “The Social Security Number must be a string of exactly nine numbers and no separator”, so for the field REF02 what kind of validation would be required? And is this value “000000000” valid for both qualifiers?
The 2010AA Billing Provider Tax Identification segment’s REF02 is qualified by REF01. Based on the qualifier used, a valid value defined by the qualifier is expected. EIN’s and SSN’s are assigned by the federal government. If the qualifier used indicates an EIN or SSN then the value submitted is expected to be a valid value as issued by the federal government. The code notes on the REF01 qualifiers clarify that the values must be numeric without hyphens.