90 days for most new, unused items with proof of purchase. Some categories are as short as 48 hours. 365 days with a Lowe's credit card or commercial account.
The basics
How
Bring it to any Lowe's store in the U.S., or start from your order history.
Different deadlines
48 hours: major appliances, air conditioners, paint sprayers, portable generators, pressure washers, chainsaws, golf carts, tile saws.
30 days: liquid paint, TVs and electronics, water heaters, most outdoor power equipment, custom blinds, HVAC, plants (not trees/shrubs/perennials), most marketplace items.
365 days: trees, shrubs and perennials; anything bought on a Lowe's credit card or commercial account.
The catch
No proof of purchase, no return. Lowe's can look it up by card, phone number or order number.
Paid by check? Refunds within 3 days are store credit only.
Lowe's Outlet sales are basically final, and outlet returns only go back to the same outlet.