The Pennsylvania Commonwealth Court held that purchasers of a property at a tax sale were not indispensable parties to a later proceeding to set aside the tax sale of the property. The Lehigh County Tax Claim Bureau conducted an upset tax sale of properties, including one where Owner resided. Purchasers successfully bid on the property. Owner then filed objections to the sale of his property, alleging that the Tax Claim Bureau did not comply with the notice requirements of the Tax Sale Law and requested that the sale be set aside. At a hearing, the Tax Claim Bureau acknowledged that it could not prove compliance with the Tax Sale Law’s notice requirements. The trial court set aside the tax sale, and Purchasers appealed to the Commonwealth Court. They argued that they were indispensable parties to Owner’s challenge to the tax sale of his property. The Court disagreed and affirmed. The Court ruled that there is no language in the Tax Sale Law to support Purchasers’ claim that they were indispensable parties to the proceeding that set aside the tax sale of Owner’s property, for which they were the successful bidders. There is, however, binding precedent that established that Purchasers, in their capacity as successful bidders, were not indispensable parties to that proceeding.