Five minutes from checkout? Run through this list first. None of these are dealbreakers on their own, but each one has, at some point, surprised a new phone owner two weeks later.

1. Carrier compatibility. If you're buying an unlocked phone, look up its supported bands and cross-check against your carrier's 5G bands. A phone that lights up on T-Mobile may show "LTE only" or hand off poorly on Verizon. Our unlocked-vs-carrier guide covers the details.

2. Storage tier. Apple and Samsung both still sell 128 GB base models. If you take a lot of photos, record video, or play modern games, 128 GB fills up faster than you'd think. 256 GB is the sweet spot for most people; 512 GB only if you record 4K video or carry your whole music library offline.

3. Trade-in deadlines. Most carrier and manufacturer trade-in offers have a 30-day clock. Have your old phone ready to ship the day the new one arrives, not "in a couple weeks."

4. Return window. Apple and Samsung give you 14 days. Carriers usually give you 14 days plus a restocking fee. Amazon gives you 30 days for new-condition returns. Note which clock is running before you buy.

5. Security update commitment. Apple commits roughly six years of iOS updates per phone. Google's Pixel 8 and later, and Samsung's Galaxy S24 and later, commit to seven years. A two-year-old phone with two more years of updates is a very different purchase than one with five more. Our Support Lifespan Tracker has the lookup table.

6. What's NOT in the box. Apple no longer includes a power brick. Samsung no longer includes a power brick. If your current charger is older than five years, factor in a $20–$30 fast charger purchase.

7. Insurance / AppleCare math. AppleCare+ is roughly $200 over two years for a flagship iPhone. Samsung Care+ is roughly $190. Realistic question: is your phone usually fine, or do you crack a screen every 18 months? If the latter, the math works. If the former, it usually doesn't.

8. Existing accessories. USB-C is now the standard on every iPhone (since the iPhone 15) and every Android phone. If you have a closet full of Lightning cables, that's not a reason not to upgrade — but it is a $25 cable-replacement cost worth knowing about.

That's it. Five minutes well spent.