How to Top Up and Renew a US Prepaid SIM: T-Mobile and Lycamobile Guide

2026-11-06

The short answer: most US prepaid plans run on a 30-day cycle. Renew before the cycle ends to keep your data and your number. T-Mobile, Lycamobile, and AT&T all support online and in-app top-ups, plus refill cards you redeem by phone. For longer stays, auto-renewal is the easiest option. Exact amounts and offers vary — always confirm at the time of purchase.

1. Top-up vs. renewal: not the same thing

• A top-up adds money (balance) to your account. A renewal uses that balance — or a saved card — to pay for the next 30 days.
• Some cards don't renew automatically when you add money; you have to renew the plan manually. Others renew on their own once auto-renewal is switched on.
• Before you buy, ask two things: does the balance expire, and is there a grace period after the plan ends?

2. T-Mobile prepaid: how to refill

• Guest refill on the website: no login needed — enter the phone number, pick an amount (refill cards generally start at $10), and pay by card.
• T-Life app: log in and refill from the billing section. You can save a payment card so the next refill is faster.
• Refill cards: sold at grocery stores, drugstores, and convenience stores. Scratch off the PIN and dial #ADD (#233) from your T-Mobile phone, or call 611 and follow the prompts.
• AutoPay: turn it on in the app and the plan renews automatically each cycle — no monthly reminder needed.

3. Lycamobile: how to recharge

• Quick Recharge on the website: click Quick Recharge at the top right, enter your number, and choose a plan or a credit top-up. Cards and digital payments are accepted.
• My Lyca app: log in, tap Top-up to recharge, and switch auto-renewal on or off from the dashboard.
• Voucher PIN: dial 321 and enter the code when prompted.
• Check your balance with *611#, and your remaining plan allowance with *619#.
• Auto-renewal usually comes with a discount — confirm the current offer at purchase. One more thing: a Lyca number with no use for over 60 days can be deactivated, so a top-up counts as use and keeps the line alive.

4. AT&T prepaid: how to refill

• Refill and renew on the AT&T website or in the myAT&T app, with an autopay option.
• Refill cards are sold in stores and supermarkets — follow the instructions on the card to redeem.

5. Checklist: avoid renewal surprises

• Top up 2–3 days before expiry, not on the day service stops: once you're offline you may not receive verification codes, and logging into the app gets harder.
• Confirm the payment landed: check your balance or wait for the carrier's confirmation text — don't assume.
• You can top up from abroad: website and app refills only need an internet connection, no US IP address. Redeeming a physical refill card needs signal on the phone itself.
• Leaving in a few days? Ask whether there's a small data add-on or a short extension instead of a full month — confirm availability at purchase.