You have to comply with the subpoena for business records.  Discovery is part of litigation.  Either party can request documents, subpoena records, etc. in order to obtain information that can be used in support of their case. If the opposing party in your case does not have an attorney, he/she cannot issue a subpoena unless the court has authorized it.  If the opposing party has an attorney, the attorney can issue a subpoena.If the opposing party in your case has not complied with the above requirements for issuing a subpoena, then you have grounds to challenge the validity of the subpoena.  If possible, try to have the subpoena invalidated in court prior to the deadline for producing the records.