Returned remittances which are unclaimed for a period of ten months, counting from the date of delivering the return-remittance notice to the remitter, shall be turned over to the state treasury.

自退汇通知投交汇款人之日起满十个月未被领回的汇款，上缴国库。

youdao

Remittances which are unclaimed when a period of ten months expires, counting from the date of delivering the return-remittance notice to the remitters, shall be turned over to the state Treasury.

自退汇通知投交汇款人之日起满十个月为被领回的汇款，上缴国库。

youdao

Flowers, Roberts ruled that when a mailed notice of a tax foreclosure is returned unclaimed, a state must take additional reasonable steps to notify the property owner before selling his property, if practicable.

FORBES: Magazine Article

Many states have laws that deem unused gift cards abandoned property, which if left unclaimed for a certain period, can be taken into the state treasury's general fund, just like an unclaimed or abandoned bank account.

FORBES: Retail

Go to unclaimed.org and click on your state on the map.

WSJ: Search for Unclaimed Money