I've had several checks that I've written in the past go un-deposited for over a year. Is it worth it to have "Void after 180 days" printed on my checks? I know that banks are not obligated to honor a check after 6 months but my question is has anyone had experience where this has happened. i.e a check with this on it was refused because it had expired.
While you can print that on the check, it isn't considered legally binding.
If you are concerned about a check not being deposited in a timely manner, consider purchasing a cashier's check instead. This doesn't solve the problem per se, but it transfers responsibility of tracking that check from you to the bank.
Your bank has discretion to honor checks after 6 months, so you should talk to your bank about their specific policy.
In general, banks won't accept "large" stale checks. The meaning of "large" varies -- $25,000 in NYC, as little as $2k in other places. Banks that service high-volume check issuers (like rebate companies) reject checks at 180 days.
For business purposes, I think some banks will create accounts for specific mailings or other purposes as well. (i.e. 2011 refund account) The accounts close after a year.