A payment service system may include a server that manages firmware updates for payment devices such as payment readers. A payment reader may access a firmware manifest including a listing of current firmware assets stored at the payment reader, and send the firmware manifest to the server. The server may compare the firmware manifest to available firmware bundles, which are ordered combinations of firmware assets that have been released for usage by payment readers. Some of the bundles may be blocking bundles, while some are non-blocking. If a payment reader is to be updated with a blocking bundle, it cannot process payments during the update. If the update is not a blocking bundle, the payment reader may continue to process payments.