Capture Postcode data

Hi guys. I’m attempting to capture postcode data through voice on my voiceflow. It will be UK postcodes so it is alphanumeric, i.e. EC1A 1BB. Right now, Alexa will transcribe it as “e. c. one a. one b. b.”, which is not the ideal format I’m looking for. Is there anyway to to preserve the numbers as numbers and the letters as letters (without full stops)?