H2O Unltd USA RTR top-ups for United States start at $28.95, with 6 plans up to $85.66 on this page. On credit per dollar it ranks 5 of the 9 main United States operators today. Prices checked 8 November 2026.
| Plan | On the phone | You pay | |
|---|---|---|---|
| H2O Unltd RTR | $20 | $28.95 | |
| H2O Unltd RTR | $30 | $43.11 | |
| H2O Unltd RTR | $35 | $50.21 | |
| H2O Unltd RTR | $40 | $57.30 | |
| H2O Unltd RTR | $50 | $71.48 | |
| H2O Unltd RTR | $60 | $85.66 |
Live from H2O. Prices are in US dollars and include our service fee; nothing is added at checkout.
You can refill an H2O prepaid number online from the UK in minutes: enter the 10 digit US number, choose a H2O Unltd USA or H2O Paygo top-up and pay by card or wallet. Top-ups start from $28.95 and the live balance goes straight to the line. H2O runs on US networks and the number dialling code is 1.
Last checked: October 2026
Slashtel lets you refill an H2O prepaid number without the account holder doing anything. You type the US number, the service detects H2O, you pick a refill and pay. The recipient keeps their existing SIM and line.
H2O is a US prepaid brand, so a refill simply adds credit or a plan to a line that is already active. If you are helping family in the United States keep their service running, you can do the whole thing from your own phone or laptop.
H2O refills come in two groups. H2O Unltd USA RTR is the unlimited line, and H2O Paygo RTR is the credit line. Both add to the existing prepaid number, and every amount shown is in US dollars with nothing added on our side.
On the H2O Unltd USA RTR line you can send 20, 30, 35, 40, 50 or 60 US dollars of refill value. On the H2O Paygo RTR line the choices are 15, 30 or 100 US dollars. The recipient's line stays as it was, and the chosen refill is applied to that number.
These are refills, not new SIM cards. They suit a prepaid line that already has a H2O number and needs topping up because the balance or plan period is running low.
A H2O number is a 10 digit US mobile number. Write it without a leading zero, because US numbers do not use one. Adding the country code 1 is optional on our form, but the ten digits after it must be exact or the refill can land on the wrong line.
A number such as (201) 555-0123 is the format you will see on US paperwork and messages. International format is +1 201 555 0123. Either works, as long as the ten digits match the phone.
Double check with the person receiving the top-up before you pay. A prepaid refill goes to the number you entered, so a digit in the wrong place sends it somewhere else.
Most refills complete quickly, but a failed order is usually down to a number that does not match a H2O line, a card that the bank declined, or a temporary problem at the operator. Check the number first, then the payment, then try again.
If the number is correct and the payment went through but the balance has not moved, give the H2O line a few minutes and check again. Keep your order confirmation so you can quote it if you contact support.
If something looks wrong after payment, get in touch and we will look at the order with you.
You pay by card, Apple Pay or Google Pay, and the payment is taken on our side, not on the recipient's phone. You do not need the H2O account password, and the person in the United States does not need to share any banking details with you.
That keeps it simple for family top-ups. The refill is tied to the phone number, and the operator is detected automatically, so you do not have to choose a network manually.
Prices start from $28.95 for H2O refills. Check the amount on screen before you confirm, especially when you are sending to more than one US number.
Yes. Enter the 10 digit US number, the service detects H2O, and you choose a H2O Unltd USA or H2O Paygo refill. Pay by card, Apple Pay or Google Pay. The top-up goes to the existing prepaid line, so the recipient does not need to do anything.
On H2O Paygo the smallest refill is 15 US dollars, and the H2O Unltd USA line starts at 20 US dollars. Paygo also offers 30 and 100 US dollars, and Unltd USA offers 20, 30, 35, 40, 50 and 60 US dollars. The live from price is $28.95.
No. You only need the US mobile number. The operator is detected from that number, and payment is taken on your side by card, Apple Pay or Google Pay. The recipient does not share a password or bank details, and no USSD code is needed.
Use the 10 digit number without a leading zero, for example (201) 555-0123, or with the country code as +1 201 555 0123. The ten digits must match the phone exactly, because the refill goes to the number you enter.
First check the number you entered, then check whether the payment was declined by your bank. If the number is right and the payment cleared, allow a few minutes and check the balance again. Keep your order confirmation and contact support if the line still shows no refill.
Enter it with the country code +1. A number written locally as (201) 555-0123 becomes +1 201 555 0123. US mobile numbers have 10 digits after the country code. The example is a format guide, not a real number.
Enter the number with the country code, pick a plan and pay by card. The operator is detected automatically and the credit goes straight to the phone. You do not need an account or a bank account in United States.
Plans currently start from $28.95 and go up to $85.66, including our service fee. The exact price is shown before you pay, with no extra charges at checkout.
Yes. Slashtel tops up any prepaid H2O number in United States, your own or a family member's. You only need the number; the person does not need an account.
Recharges are delivered instantly and cannot be reversed once they reach a valid number, so check the number before you pay. If the operator rejects the number, Slashtel resends or refunds you in full.
Prices on this page are in US dollars and include the Slashtel service fee. At checkout your card may be shown and charged in your local currency, and the exact amount is confirmed before you pay.
Yes. Payments are processed by Stripe with 3D Secure where your bank supports it, and Slashtel never sees or stores your full card details.
Most recharges arrive within a few minutes. If the phone is switched off, the credit lands when it next connects. You get a confirmation email with your order reference.
If the operator rejects the recharge, we resend it. If it still can't be delivered, write to esim@slashtel.com or message us on WhatsApp with your order reference and we'll sort it out.