Some in the replies below claim their travel credit disappeared after saving this offer.
It doesn’t seem to affect your travel credit if the expiry is next year.
Save the offer to your eligible Card and spend online or in-store at Harvey Norman or online at travel.americanexpress.com.au by 31/12/2021 to receive your purchase amounts back as a credit, up to $400 credit per Card. Exclusions apply.
For reference, these are the terms and conditions.
Offer valid for payments in-store at Harvey Norman or online at harveynorman.com.au. Offer valid at Australian locations and website only.
Excludes all payments made at Harvey Norman Big Buys, Harvey Norman Commercial Division, Harvey Norman Insurance Replacement Division, Harvey Norman Security and Domayne locations.
Excludes payments made online at Harvey Norman Photo Centre.
Excludes payments made for Miele products.
COVID-19 restrictions may affect the availability of in-store locations. Please check stores.harveynorman.com.au for more information.
American Express Travel Online:
Offer valid for payments made online at travel.americanexpress.com.au.
Excludes purchases of Bundles.
Excludes payments made via phone (including, but not limited to, payments made via Platinum Travel Service or Centurion Travel Service).
Payment can be made with a combination of your American Express Card and Membership Rewards points, Travel Credit or discounts. However, only the amount charged to your Card is eligible for the offer.
Excludes bookings where payment is made directly to the supplier (such as FINE HOTELS & RESORTS or The Hotel Collection).