A mail processing system having a postal security device (PSD) that can be dynamically configured to support multiple customers and carriers is provided. Meter records are maintained at a data center. Each meter record includes information necessary to configure the PSD for a particular customer and/or a specified carrier. The data center provides a requested meter record to the PSD, which then is configured according to the meter record. Once loaded with a complete meter record, the PSD will function as a traditional PSD and mail processing can be performed by the mail processing system using the configured PSD. All accounting takes place locally in the PSD, and all records maintained in the meter record are updated locally in the PSD. Upon completion of the mail run, the updated meter record can then be uploaded to the data center until the next mail run that requires the meter record.