Is your phone ready to move abroad?
Answer a few questions about your phone and your move. The checker tells you whether your phone can take a local SIM, and which setup keeps your US number working for bank codes.
Check if your phone is unlocked
A locked phone won't accept a SIM or eSIM from another carrier, so you can't add a local plan when you land. US carriers lock phones sold on installment plans and unlock them once you meet their rules.
On an iPhone, open Settings, tap General, then About, and scroll to Carrier Lock. "No SIM restrictions" means the phone is unlocked. A carrier name or "SIM locked" means you need to call that carrier.
On Android, the menu depends on the brand. Samsung puts lock status under Settings, Connections, SIM manager. Pixel uses Settings, Network & internet, SIMs. Some phones don't show the status at all, and the surest test is a SIM from a different carrier. If the phone gets signal and can place a call, it's unlocked.
Unlock requests take anywhere from a few minutes to several business days, and an unpaid balance adds more delay. Start two weeks before your flight, and read the current policy for the carrier that sold the phone: AT&T, T-Mobile or Verizon.
Check if your phone supports eSIM
An eSIM lets you install a data plan before you board, so your phone works the minute you land. On an iPhone, open Settings and tap Cellular (or Mobile Service). An "Add eSIM" option means the phone supports it. US iPhone 14 and newer models are eSIM-only and have no SIM tray, while versions sold in other countries can differ.
On Samsung, look for "Add eSIM" in SIM manager. On Pixel, look for "Download a SIM instead" under SIMs. Budget models and some regional versions skip eSIM, so check the manufacturer's spec page for your exact model number.
Check that it can run two lines
You'll want your US number and a local data line active at the same time. The US line receives bank codes and calls, and the local line carries your data at local prices.
iPhones with eSIM support can run two lines at once. Apple's spec page for your model lists the exact combination, either two eSIMs or one eSIM plus a physical SIM. On Android, support varies by model and carrier firmware. If SIM manager shows two lines with separate toggles for calls and data, you're set.
Will my phone work in Mexico or Europe?
A recent iPhone, Pixel or Galaxy sold in the US covers the LTE bands that major carriers use in Mexico, Europe and most of Latin America. Older phones and budget models can miss a band or two. You'll notice that as weak signal indoors more than as no signal at all. Compare your model's spec page with the band list your destination carrier publishes before you buy a plan.
Keep your US number working
Don't cancel your US line before you move. Banks, brokerages and email recovery still send codes by text, and many of them reject Google Voice numbers. The Google Voice abroad guide covers the two-line setup that keeps those codes arriving, and the free 47-item checklist covers the rest of your move.
The Exit Nerd Guide includes the full version of this checker, with screen-by-screen steps for installing an eSIM, setting up both lines and moving your number to a cheaper carrier.