This document proposes a lightweight payment verification system using blockchain technology for IoT devices. It describes implementing a basic payment verification blockchain coding in Python and deploying it on an ESP8266 IoT development kit. The system uses RFID cards to store user payment information and verify transactions in real-time. When an RFID card is scanned, the user's data is added as a new block to the blockchain ledger. Each new block contains a hash of the previous block, linking the blocks together and making the record tamper-proof. This allows secure payment verification even on low-powered IoT devices.