       // Attempt to add credits to card
       if (updateAndVerify(addr, card)) {
         // OK Beep
-        //BEEP(1);
+        Serial.write('F'); // finish communication
       } else {
         // Reset credits on vending machine
         rfid_transmit('S', credits_in_machine);

    // Request and read data from other party
    Serial.write(command);
    while (!Serial.available()); // Wait till other side transmits a C
    if (Serial.read() != 'C')
      return;
    number = rfid_raw_read();
    if (recieve_error == 0) { // Received correctly, return value

            // Could not update machine credits - attempt to save credits to card again!
            card.credits = current_credits;
            updateAndVerify(addr, card);
            Serial.write('F'); // finish communication
            BEEP(4);
          }// else {BEEP(1);}
        } else {
