Well it's subject to interpretation.
https://www.harborfreight.com/customer-service-return-exchange.html#6
"WARRANTY INFORMATION
Hand Tool Lifetime Warranty
We guarantee our Hand Tools to be free from defects in material and workmanship for the life of the product. Limitations apply. Harbor Freight Tools will replace any hand tool that fails to properly work during the lifetime of the original purchaser. In the event an identical item is not available as a replacement: Harbor Freight Tools reserves the right to substitute a substantially similar item in its place. This warranty gives you specific legal rights and you may have other rights that vary from state to state."
They don't specifically say you need a receipt but offer no guidance on what proof is required to show you are the original purchaser. One is left to assume proof would be a receipt. But then again it could vary from state to state.
By comparison the
Limited 90-Day Warranty states
"To take advantage of this warranty, the product or part must be returned to us with transportation charges prepaid. Proof of purchase (e.g. in-store receipt or packing slip/invoice), date and an explanation of the complaint must accompany the merchandise."
Some people have reported they did not need to produce a receipt to get an Icon tool replacement, others say they did.
Did you give the cashier your phone number when you bought the Icon tool? If so they can use it to look up your purchase. You also should have gotten an email copy. The receipt email can be found with a search for
[email protected]