Lost a cashier’s check? Don’t panic. The solution may not be as straightforward as issuing a stop-payment but there are simple actions you can take to ensure the money gets where it needs to go without facing a major loss.
First, contact the issuing bank to inform them of the situation.
You will be asked to make a Declaration of Loss, a statement made in record under penalty of perjury, stating that you, the declarer, lost possession of the check, to the “obligated bank” (the bank that issued the cashier’s check). 
You then typically wait up to 90 days after which the bank will release the funds to whoever has a claim on them (the payee or the account owner). 
Often, the bank requires an Indemnity Agreement in order to issue the replacement check. This agreement guarantees that you are liable for any losses in the event that someone finds and cashes the check.  This agreement is often vital to receiving the replacement check as banks don’t want to risk having two checks in circulation.
Since you are now responsible for any losses that the bank would have faced, if someone finds the check, you are left to pay the full amount of the cashier’s check again.
To alleviate the risk having to pay twice, buy a surety bond. This bond covers the amount of the lost check. You pay 2% of the bond amount (with a minimum of $100) and the bond company covers the bank’s losses in the event that the original check is cashed.
To obtain a surety, the cashier’s check must be lost for at least 30 days and should not have been endorsed. Learn more about lost cashier’s check bonds here. If you have any questions, our staff at Surety1 will be happy to help.
[1. Cornell University Law School, Legal Information Institute. Lost, Destroyed or Stolen Cashier’s Check, Teller’s Check, or Certified Check. Retrieved from https://www.law.cornell.edu/ucc/3/3-312]
[2. U.S. Department of the Treasury. Retrieved from http://www.helpwithmybank.gov/get-answers/bank-accounts/checks-cashiers-checks/faq-bank-accounts-cashiers-checks-01.html]
[3. About. Cashier’s Checks. Retrieved from http://banking.about.com/od/Cashiers-Checks/fl/Lost-or-Stolen-Cashierrsquos-Check-No-Longer-Need-It.html]