Your own Credit Card AI agent, Amex Updates and more

Hey guys, hope you're having a great Sunday. This is issue three of CardStack Insiders.

I've been working on Stack, the new CardStack AI agent (more on that below), and I pulled together what's moving in points, miles, and card-linked deals.

If you have ideas or app feedback, reply any time. I read everything. Forward this if it helps someone, or subscribe here if a friend sent it. Thanks for reading.

Checked bag fees are up again across the majors: United and JetBlue led this month, then American, Delta, Southwest, and Alaska followed. On a typical domestic trip you're now in the ballpark of $45 for the first bag, ~$55 for the second, and up to $200 for a third. Airlines are blaming fuel—which I'll buy or not—but I don't expect these to unwind when oil dips. Bag fees don't work that way.

If your card already covers the first checked bag for you and your companions, that perk just got more meaningful. If you're shopping or comparing, we keep our best cards for flights updated (airline co-brands included). Run the numbers for a family of four with checked bags both ways on one trip and it'll sting.

Referrals capped at five per year per card. As of April 8, referral bonuses on each Amex card are limited to five successful referrals per calendar year. On some products that can work in your favor (for example, five referrals at 30K on Platinum is 150K, above the old 100K-style ceiling). On others, like Hilton or cash-back cards, the total you can earn from referrals may drop.

Platinum Member Airfares. This is mostly a new name for the old International Airline Program: roughly 10% off premium cabin fares booked through Amex Travel with a long list of airlines. I've also seen some domestic economy discounts (Delta shows up sometimes), so it's worth a quick search before you book cash tickets.

Lufthansa lounge access ends October 1 for Platinum and Centurion. Plan around that if you rely on those lounges abroad.

A few offers are winding down this month.

Capital One Venture Rewards: 75,000 miles plus $250 toward Capital One Travel after meeting spend. Public bonus ends April 14. Read terms on the issuer site before you apply.

There's another elevated offer on a no-annual-fee card I won't name here (issuer rules), but it's an easy $250 or 25,000 points if you qualify. Check CardMatch-style tools or the issuer's own pre-qual flow if you're curious.

Hilton: one public offer is up to 175,000 Hilton Honors points; it ends April 15. Pull up the current Hilton card page on the issuer site and confirm the offer in your name before you apply.

Citi ThankYou: the 25% bonus to Avianca LifeMiles and 30% to Virgin Atlantic both end April 18. If you were waiting to move points, next week is the deadline.

Choice and Preferred Hotels (coming): Citi is tightening transfer ratios to Choice and Preferred Hotels. Preferred is moving from 1:4 to 1:2 (half as many hotel points per ThankYou point). Choice moves from 1:2 to 1:1.5 (a 25% cut). If you already have a redemption in mind, moving points sooner is the safer play. For context on the program, see our ThankYou Rewards page. Confirm current ratios on Citi's site when you transfer.

Before you move points, check our active transfer bonuses tool so you know what's still running and when it ends.

• AllTrails: 50% back, up to $40 (ends 7/5)
• Delta Vacations: $200 off $1,000 (ends 6/30)
• DirecTV: $50 off $100, up to 2 times (ends 4/30)
• DISH Network: $85 off $85 (ends 5/15)
• Marriott: $150 off $375 (ends 7/22)
• Rover: $50 off $100 (ends 6/30)
• Turkish Airlines: $200 off $1,200 (ends 6/30)
• Viator / TripAdvisor Experiences: 8% off, up to $125 (ends 4/30)

Tip: The CardStack browser extension for Chrome and Safari can add eligible Amex and Chase offers to your cards in one click while you are on the bank website, so you don't have to add them manually.

CardStack iOS v1.2 should be on the App Store sometime this week. This one has been a long time coming, and it starts to deliver on the vision I have for CardStack: a proactive, agentic experience that helps you get the most out of your cards, not just track them.

In this version you get Stack, an AI agent that knows your cards, credits, offers, points, and transactions (assuming you've connected your data). It's built to help you truly maximize what you carry. Stack can:

• Remind you to use a credit
• Update your points balance
• Mark your credits as redeemed
• Give you your full portfolio report
• Find cheap flights and help you decide cash vs. points
• Compare your cards
• Suggest the best way to redeem points
• Help you plan a trip
• Suggest the best card to use, or the best card to sign up for

… and much more

It's powerful, and it's not just a chatbot. It's an agent. I can't wait for you to try it. For release notes and the full timeline, see What's New. If CardStack has been useful for you, I'd love a rating and review. It helps a ton.