If I have checks for on account that doesn't exist anymore, can I safely throw them away?
Yes, but I'd sill shred or burn them just in case. identity theft is the biggest crime today so having as little known about you the safer you are
Make sure you break them or cut them. my husband threw some old checks out and some one was using them at little check cashing places and we had a lot of trouble with scam.
Yes, you can safely throw them away. Before you do, burn em'..cut em' into pieces.
I would check with your current bank also, some banks will take them and recycle them for you and give you a little bit of money towards new checks NOT all banks do this, but other wise I would shred or cut them up before throwing away.