Lindsey answered on 3.26.16:
While your expired Kohl’s Cash won’t work online after the redemption period has ended, you can still save big on your online purchase by redeeming one of our Kohl’s promo codes our Kohl’s promo codes right at checkout. We’ve scoured the web for some of the best deals at Kohl’s just so you don’t have to miss out on great savings even though your Kohl’s Cash has expired.
Check out today's top sitewide deals to save at Kohls.com:
Since shoppers can only receive Kohl’s Cash during promotional dates, it makes sense that Kohl’s Cash is only redeemable during certain periods, too (which typically last between 6-12 days). Just be sure to check out on Kohls.com before 11:59 p.m. on the last day of the redemption date in order to use your Kohl’s Cash online, and keep your Kohl’s Cash on you for in-store purchases up to 10 days after the promotional period.
If you always end up with expired Kohl’s Cash, keep track of those pesky expiration dates by downloading the Kohl’s Cash app or by scanning the expiration dates on Kohl’s in-store Cash, Kohls.com Cash, and Kohl’s mobile wallet Cash.