I posted some books today and one PB came up as a HC. I checked the ISBN several times and I had entered it correctly. The PB had only one ISBN in it on the reverse of the title page.

I'm not overly concerned, if it gets requested I'll let the requester know it's a PB, but has anyone else had this happen? And should I be doing anything about this? 

And I do apologize for posting this first in the Member's Thoughts forum by mistake. Very sorry.

You need to remove that posting and repost it without an ISBN. When you list a book you confirm that the ISBN and binding type match when yours clearly doesn't. If someone is requesting a hardback they are usually doing so for a reason, so getting a PB telling them that it is really  a PB does not accomplish anything. The book MUST be listed correctly to start with.

Thanks, I did work out how to post a book without an ISBN and used that method to post it correctly. Seems Like I learn something new every day at PBS.

The other thing you might want to do is check that it is not an ARC (Advance Reader Copy).  Many times if your paperback comes up with a hardcover ISBN, it's because it is an ARC, which are not allowed to be posted here.   It will say ARC or Uncorrected Proof or Not For Resale, or similar somewhere on the cover. 

But as long as you know it's not an ARC, Post without ISBN is the way to go. 

Seems Like I learn something new every day at PBS.

Me too.  Isn't it wonderful? I love learning how things. 

Thanks for your input but itt wasn't an ARC. I'm a reviewer and familiar with ARCs. This wasn't one, also I remember buying the book whilst on a holiday.

Don't assume it's an ARC, I have probably half a dozen books recently matched everything but PBS said they were HC and mine were PB. I have never owned an ARC, but read plenty when a neighbor had a brother who was a book critic.  I hate all the time it takes to enter books with no iSBN, esp when that's not the real case!