Underwriter

An underwriter is an intermediary between buyer and seller who is trained to evaluate risk and liability and assign appropriate classifications to a proposed business relationship.

Specifically, an underwriter in the merchant services industry will evaluate the risk that a processor will take on if they were to agree to provide service for a new applicant.

If the underwriter classifies the new merchant as "high-risk" the processor may decline the application, or require additional measures to mediate or lessen the risk.

Underwriters may order ACH delays or rolling reserves to lessen the risk associated with an otherwise unacceptable account.

More web-definitions of "underwriter" can be found at Google