Reminder: register for 5% cash back each quarter (please)

Since converting my Citi ThankYou Preferred card to a Citi Dividend Platinum Select card in January, I've been carrying all 4 of the "classic" rotating-category 5% cash back cards. In addition to the Platinum Select, that includes the US Bank Cash+, Chase Freedom, and Discover it (formerly Discover More).

Each of the cards has its own advantages and disadvantages, but there are several recurring, powerhouse bonus categories each year. Gas stations are typical 5% cash back categories for the Freedom and it cards, while Citi has offered 5% cash back at drugstores for the last two years, and US Bank allows you to earn 5% cash back on Kiva loans, for an easy $400 per year (minus any defaulted loan amounts).

All of which you already know.

Discover won't award bonus cash back for purchases made prior to registration

Chase is famous for retroactively awarding the 4 bonus Ultimate Rewards points to Freedom cardholders who register up until the registration deadline, typically 2 weeks before the end of each quarter.

My public service announcement today is that Discover does no such thing.

The idiot that I am, I went out at the beginning of July and made 3 gas station purchases at my trusty local service station. A few weeks later – before my July statement had closed – I realized to my horror that I hadn't registered for the quarter's bonus categories. When my statement closed today, my hopes for redemption were dashed:

There was no 5% cash back. There was barely any cash back at all. Meaning I wasted $1,500 in spend bandwidth and barely broke even, after liquidation costs.

Do yourself a favor: register for cash back every quarter, before you start spending!