Prepaid SIM card: what it is, what it costs, and when an eSIM is cheaper

What is a prepaid SIM card?

A prepaid SIM card is one you pay for before you use it. You buy credit, or a fixed bundle of data, minutes and texts, and when it runs out or the days expire, service stops until you top up. No bill turns up afterwards. The UK networks whose pages we read on 10 November 2026 also say there's no contract and no credit check.

That's the whole difference from a contract: the money goes in first.

For travellers it matters more than it sounds. Almost every SIM sold to tourists is prepaid, and so is almost every travel eSIM: you pay for 10 GB or 30 days up front, and the plan simply ends when either runs out. Prices below come from our own carrier pages, country guides and verified eSIM price data, and each one says where it came from. We haven't bought these SIMs ourselves.

Prepaid, contract or SIM only?

Three labels get mixed up, and the UK adds a fourth.

SIM only describes what's in the box, not how you pay. It means a SIM with no phone attached, and it can be a contract or prepaid; EE files its prepaid range under "pay as you go SIM only". British networks call prepaid "pay as you go", which our pay as you go SIM card guide covers network by network. American carriers say prepaid against postpaid.

What does a prepaid SIM cost?

Searches for a prepaid SIM card come mostly from Australia and Canada, so they go first, followed by the US and the UK. The local figures are the carriers' own, from pages we read on the dates shown.

The Boost price was a sale that ended in mid-October, which is rather the point. Prepaid prices are built from promotions, bonus data and first-month discounts, and the sticker moves faster than any comparison site can keep up. Three's £10 pack was 60 GB when we read the page on 8 October and 30 GB a month later.

The small print differs too. Telstra says its prepaid service is for use in Australia only and that most of its plans cap download speeds. Vodafone Australia says you need an international passport to activate a Prepaid Starter Pack, which it sells at its Sydney, Brisbane and Perth airport stores and at over 20,000 other outlets.

Buying a prepaid tourist SIM when you land

This is the classic prepaid travel SIM card, and it still wins in plenty of countries. Two things trip people up.

The first is paperwork. The US asks for no ID. Japan and Vietnam want a passport. Vodafone Australia wants one too, so don't assume a rule from one carrier holds for the whole country. Our how much is a SIM card page lists the ID rule next to the price for twelve countries.

The second is delivery. Telstra posts physical SIMs and says they usually take about five days in metro areas. No use if you land tomorrow. Buy the card at an airport counter or a shop in town, or buy an eSIM instead.

And whichever you choose, the phone must be unlocked. A locked phone refuses another carrier's SIM, plastic or digital.

For country-by-country airport prices against the best eSIM, see our international SIM card guide. We won't repeat that table here.

Prepaid eSIM: the same deal without the card

A prepaid eSIM is a prepaid plan you download rather than slot in. There are two kinds.

Carrier prepaid eSIMs. Several local networks sell their prepaid plans as eSIMs. Telstra sells a prepaid eSIM beside its physical SIM. Three UK emails eSIM details so you can start straight away, and Vodafone UK lists every Pay as you go Plus plan as available with eSIM. Boost Mobile sells its eSIM only inside its app. T-Mobile's U.S. Pass eSIM for visitors was $50 for 30 days, though you have to be in the US to buy and activate it; our T-Mobile page relied on search excerpts of T-Mobile's site for that.

Travel prepaid eSIMs. Airalo, Nomad, Saily and Holafly sell prepaid eSIMs online, so you install one before you fly and land connected. These prices come from our verified data, checked 13 to 17 August 2026:

Canada is the clearest case for the eSIM: Nomad's 10 GB month costs less than the roughly $25 airport SIM. In Australia, Nomad's 50 GB is $32 against about $18 at the airport, per our Australia guide, but we don't know how much data that airport SIM carries, so we can't call it.

Most travel eSIMs are data only, with no local number. If you need one, for a landlord or a restaurant booking, a carrier prepaid SIM or eSIM is the way to get it. Our data only SIM card guide explains how to keep your home number running alongside.

Which prepaid SIM card would we pick?

For a trip of a week or two on a phone that takes eSIM: a travel eSIM bought at home, sized up rather than down, since the 50 GB plans are far cheaper per gigabyte than the small ones. Check your phone on our eSIM compatible phones list, then compare countries on cheapest eSIM.

For a long stay, a local number, or a trip where the network matters: a local prepaid SIM card. Telstra claims the widest coverage in Australia, and our USA guide found Verizon is the network for national parks. No travel eSIM we track names its host network.

For a phone with no eSIM: the plastic card, bought on arrival, passport in hand.