Can you add a second commuter pass to the same IC card?

I have a question that I can't seem to find the answer to in the commuter pass terms and conditions.

I currently have a 3 month commuter pass I'm using on the Hankyu line(Osaka), and would like to add another 1 month pass to ride the Osaka Metro. Extending my trip for the next month.

Can I add a second commuter pass to my current IC card, or should I use a second IC card for the Metro for the next month?

Thanks in advance, I just don't want to get stuck at a ticket machine in the busy morning rush buying a commuter pass.