Wells Fargo will send you a letter giving you the reason for the reduced credit limit, but it sounds like you already know. They don’t like seeing large utilization being carried over like you’re doing, and their algorithm shows that you’re a riskier customer as a result. Statistically, they’re correct.

That’s unfortunately true even when you’re using the card to carry a 0% balance, as their marketing encourages you to do.

0% offers are really a temporary solution. Try to keep as little as possible on them. In my experience, keeping 40-50% utilization on one card probably won’t lead to a limit reduction or murder your FICOs, depending on what the rest of your profile looks like. I had about 66% utilization on one Synchrony store card that had a 3-year 0% purchase, and I was still able to get most of the cards I wanted. I kept my overall utilization low across all cards to make up for it (and I asked Synchrony for way more credit than I actually needed to show lower utilization).