How do I know which Sunrise multicard SIM card, extra SIM surf & talk is active at present? 

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To find out which Sunrise multicard SIM card is active, simply enter the following command: *101# +call button. Shortly afterwards, you will receive a message containing the ID of the active SIM card: "Sunrise multicard #n Status active". The SIM card with the number 1 is the main card, whilst those with the numbers 2 to 5 are the additional cards.    

You will find all the information on the Sunrise multicard here: