I found this offer on my Amex Hilton card, but not on my other ones, so YMMV.
$10 back - H&R Block - Digital Tax Solutions
Spend $30 or more, get $10 back
Get a one-time $10 statement credit by using your enrolled Card to spend a minimum of $30+ in one or more transactions online at hrblock.com by 4/30/2018. See terms for exclusions.
Offer valid only at hrblock.com. Includes H&R Block’s online & desktop tax software products, Tax Identity Shield, H&R Tax Preparation App and Best of Both service. Valid only on US website. Excludes H&R Block retail offices. Excludes Second Look Review, tax payments through payusatax.com, Expatriate tax preparation services and H&R Block Income Tax Course. Excludes authorized retailers. See merchant website for shipping policy. Some merchants may not ship to all areas. Offer is non-transferable. Must add offer to Card and use same Card to redeem. Limit 1 statement credit(s) per American Express® online account. Statement credit will appear on your billing statement within 90 days after 4/30/2018, provided that American Express receives information from the merchant about your qualifying purchase. Note that American Express may not receive information about your qualifying purchase from merchant until all items from your qualifying purchase have been provided/shipped by merchant. Statement credit may be reversed if qualifying purchase is returned/cancelled. If American Express does not receive information that identifies your transaction as qualifying for the offer, you will not receive the statement credit. For example, your transaction will not qualify if it is not made directly with the merchant. In addition, in most cases, you may not receive the statement credit if your transaction is made with an electronic wallet or through a third party or if the merchant uses a mobile or wireless card reader to process it. By adding an offer to a Card, you agree that American Express may send you communications about the offer.