This application describes a phased approach to provision eSIM profiles to a wireless device. Credentials are preloaded to an eUICC during manufacture of the eUICC and used subsequently to load eSIM profiles to the eUICC without requiring an active, real-time connection to an MNO provisioning server. Multiple bound profile packages (BPPs) can be pre-generated and encrypted by MNO provisioning servers for an eUICC and transferred to a BPP aggregator server before assembly of the eUICC in a respective wireless device. A local provisioning server in a manufacturing facility mutually authenticates and connects to the BPP aggregator server to download and store one or more of the encrypted BPPs for later installation on the eUICC. The local provisioning server subsequently mutually authenticates and connects to the eUICC to load at least one of the one or more pre-generated, encrypted BPPs to the eUICC during assembly and/or testing of the wireless device.