Same here bro, I'm also using ICICI CC since 2007. Currently I have spent some amount on my existing card and there is also some blockage due to an EMI transaction. However, the new card shows the full limit available. So it doesn't seem like a shared limit to me. Need to confirm by using it somewhere and seeing if the limit decreases on both the cards. And yeah, I will be canceling the other card since I don't need two, as you said, since I'm not deactivating the account, I don't think it will impact CIBIL score.