Only Nomad sells a São Tomé and Príncipe eSIM in October 2026, and it connects to Unitel STP, the smaller of the country's two mobile operators. Airalo and Holafly both return a dead page for the country. Nomad's catalogue is two plans: 1 GB over 7 days for US$25, and 3 GB over 30 days for US$59. The other operator, CST, is the one the national regulator has rated the best mobile network two years running, and its prepaid Netfone 1 GB pack costs 80 dobras, which is under four dollars. So the eSIM here is a landing bridge and a convenience, not the cheap option. Buy the small Nomad plan if you want to message your guesthouse from the runway, then walk into a CST shop in the city with your passport for anything longer than a few days.
Quick Pick: the Best eSIM for Sao Tome and Principe
Nomad (Sao Tome and Principe 1 GB / 7 days): The only travel eSIM on sale for the country, on Unitel STP with hotspot allowed. At US$25 it is expensive per gigabyte, so treat it as cover for arrival day and a backup line on the second network, and do the bulk of your data on a CST Netfone pack from town.
Our picks
Best overall: Nomad. Lowest per GB: Nomad. Or use the eSIM Finder.
Sao Tome and Principe eSIM Plans Compared
Indicative pricing. Tap through for live rates.
| Provider | Plan | Data | Duration | Price | Network |
|---|---|---|---|---|---|
| Nomad | Sao Tome and Principe 1GB | 1 GB | 7 days | $25 | Unitel STP |
| Nomad | Sao Tome and Principe 3GB | 3 GB | 30 days | $59 | Unitel STP |
Nomad Sao Tome and Principe Plans
Nomad: The Only Travel eSIM, On The Second Network
Two data-only plans on Unitel STP, from US$25
The whole Nomad range for São Tomé and Príncipe fits on one line: 1 GB for seven days at US$25, or 3 GB for thirty days at US$59. That is US$25 and about US$19.67 per gigabyte. Set against CST's 80 dobra gigabyte, which is under four dollars, Nomad costs six to seven times as much for the same amount of data. There is no unlimited tier, no 5 GB option and no regional Africa bundle on Nomad's page that lists the country.
The real case for it is timing and the second network. You land, the phone is already on Unitel, and you can tell your guesthouse or driver that you are through immigration without hunting for a shop. If you are booked straight onto the connecting flight to Príncipe, or arriving on a Sunday afternoon, that matters more than the price. Once you do buy a CST card, the Nomad line becomes a backup on the other operator, which is genuinely useful in a country where one network's international link can go down for half a day.
Two cautions. First, check the network detail rather than the marketing: Nomad's plan data names Unitel and tags it 3G, while its headline mentions 4G and 5G, and you will get whatever Unitel delivers where you are. Second, the validity clock is generous on the shelf, since a plan starts when it first touches Unitel or after 60 days, but short once running. Do not switch it on during the stopover in Lisbon or Luanda and expect it to be waiting for you.
Strengths
Weaknesses
Mobile Networks in Sao Tome and Principe
Two operators, not one. Some older guides describe São Tomé and Príncipe as a single-network country. That has not been true for years. The incumbent is CST, the Companhia Santomense de Telecomunicações, which celebrated its 35th anniversary at a gala in the Palácio dos Congressos in December 2025 and still runs the fixed network, the fibre and its own IPTV service, CST ON. The challenger is Unitel STP, headquartered in the Edifício Equador in Vila Maria, a name you may recognise from Angola and from Unitel T+ in Cabo Verde, both of which sit on its roaming partner list. Both are regulated by AGER, the Autoridade Geral de Regulação, which also oversees water, power and post.
Which one is better? CST says, and has said loudly, that AGER named it the national mobile network with the widest coverage, the best quality and the fastest internet for the second year in a row in April 2025. That is the operator reporting its own award, so weigh it accordingly, but it fits what the shop map suggests: CST runs twelve official stores, from the Loja Central on Largo de Água Grande opposite the cathedral down to Angolares on the south-east coast, and one in Santo António on Príncipe. Unitel's public-facing presence is thinner, and its website's tariff pages were last updated in 2019.
Why that matters for the eSIM. Nomad's plan records list a single partner network, Unitel, under network code 626 02. There is no fallback to CST. Odder still, the same records tag the Unitel connection as 3G while the page headline advertises 4G and 5G speeds. Unitel did announce a 4G launch in 2023, so 4G may well be what you get in the city, but we found no evidence of any commercial 5G in the country, and you should read the plan data rather than the banner. If Unitel is weak where you are staying, the eSIM is weak too.
What local data costs. CST's Netfone prepaid packs run for 30 days: 1 GB for 80 dobras, 2 GB for 150, 4 GB for 220, 6 GB for 300, 12 GB for 450, 30 GB for 990 and 60 GB for 1,490. A 24-hour pack gives 100 MB for 10 dobras, and Netfone Noites gives 1,800 MB for 110 dobras, usable only between midnight and 7am. If you want calls in the bundle, the Turbo +NET weekly pack is 60 dobras for 150 minutes or texts plus 500 MB, and the monthly one is 180 dobras for 600 minutes plus 1,500 MB. The dobra is pegged to the euro at 24.5 to one, so 80 dobras is about €3.27, or roughly US$3.65, and 450 dobras for 12 GB is around US$20.60. Unitel's own monthly Maxibin bundle, as last published, was 165 dobras with 900 MB, daily on-net minutes and free Facebook Flex.
The fragile part is offshore. International traffic for the whole country leaves through a very small number of submarine links. Unitel's homepage currently carries a notice that work on its international circuits would cut internet and international calls from 1am to noon across three consecutive days, while national calls and SMS carried on. When that happens, every phone on that network is affected, eSIM or local, so a second line on the other operator is not wasted money.
Before you count on an airport SIM
CST's published list of twelve stores does not include one at São Tomé International Airport, and we could not confirm a staffed counter in arrivals for either operator. Plan to buy in town. The Loja Central opens 07:30 to 19:00 every day including Sundays, and the Conceição store in the Centro Comercial stays open until 21:00 Monday to Saturday. Take your passport; Unitel's site has a dedicated number-registration section, and you should expect ID to be asked for at either operator.
Coverage Across Sao Tome and Principe
Coverage where travelers actually go:
| Area | Coverage | Notes |
|---|---|---|
| São Tomé city and the airport | Good | Both networks are strongest here, around the Sé, the market and the bay. This is where CST's busiest shops are and where you should sort out a local card. |
| North coast: Neves, Guadalupe and Lagoa Azul | Good to fair | CST has stores in both Neves and Guadalupe, a good sign for its coverage. Signal can soften on the coves around Lagoa Azul and the Tunga coastal track. |
| Trindade, Monte Café and the interior roças | Fair | The plantation country inland rises steeply into cloud forest. Towns like Trindade are covered; the higher roças and the Bom Sucesso botanical station are hit and miss. |
| South: Angolares, Porto Alegre and Praia Jalé | Fair to patchy | CST's southernmost store is in Angolares. Beyond it, toward the turtle beaches at Jalé and the boat to Ilhéu das Rolas, expect gaps. |
| Obô Natural Park and Pico Cão Grande | Unreliable | Dense rainforest and steep volcanic ground. Download your hiking route and do not plan to navigate live under the canopy. |
| Príncipe | Fair in town, thin elsewhere | Santo António has a CST store and the island's best signal. Away from the town, toward Roça Sundy and the southern beaches, coverage drops off. Check which network your lodge uses before you fly over. |
How to Choose the Right Plan
The decision here is short, because there is only one eSIM to buy and the local alternative is far cheaper. What you are really choosing is how much of the trip to put on each.
Two or three nights, mostly in the capital: the Nomad 1 GB plan at US$25 will cover messages, maps and booking confirmations, and it saves you a shop visit on a short schedule. You are paying for the convenience and you should know that going in.
A week or more: buy a CST card in São Tomé city on your first morning and put a Netfone pack on it. The 4 GB pack at 220 dobras, about US$10, or the 12 GB pack at 450 dobras, about US$20.60, covers most trips for less than Nomad's smallest plan. If you also want to ring guides, drivers and restaurants, take Turbo +NET instead, which bundles minutes with the data. Keep the Nomad plan installed for arrival day and as a Unitel backup, or skip it entirely if you are happy to be offline from the runway to the shop.
Heading to Príncipe: most visitors connect onward on the short domestic flight, often the same day they land. That is the strongest argument for Nomad, since you may not pass a shop in the capital at all. CST does have a store in Santo António, on Rua Lenta Pia, so you can still buy local on the smaller island once you arrive. Ask your lodge which network reaches it; the eco-lodges in the island's UNESCO biosphere reserve are deliberately remote, and some rely on their own WiFi more than on mobile signal.
Hiking Obô or chasing turtles in the south: no plan fixes the rainforest. Download the route to Pico Cão Grande or the trail around Lagoa Amélia before you leave signal, and carry a power bank, since electricity cuts are part of life on both islands and guesthouses may not have a generator.
Paying for things: buy the eSIM at home on a card. Cash rules once you arrive, and euros are commonly accepted at the fixed 24.5 dobra rate, so carry small notes for the CST counter and for top-up vouchers. Airalo and Holafly do not sell the country, and we found no Africa regional bundle from either that includes it, so do not assume a multi-country plan from the mainland leg of your trip will carry over.
Frequently Asked Questions
How many mobile networks are there in São Tomé and Príncipe?
Two. CST, the Companhia Santomense de Telecomunicações, is the incumbent and the larger network, with twelve stores across both islands. Unitel STP is the challenger and the network that Nomad's eSIM connects to. Some older travel guides say there is only one operator; that is out of date. In 2025 CST reported that the regulator, AGER, had ranked it best for coverage, quality and speed for a second year, so if you can only have one local card, CST is the safer bet.
Is the Nomad eSIM worth it when a CST card is so cheap?
For a short stay or a same-day connection to Príncipe, yes. For anything longer, only as a backup. Nomad charges US$25 for 1 GB, and CST's Netfone pack gives the same gigabyte for 80 dobras, roughly US$3.65 at the euro peg. The eSIM earns its price in the first hours, before you can reach a shop, and as a second network afterwards. It loses badly as the main data plan for a two-week trip, where 12 GB from CST costs less than Nomad's smallest plan.
Can I buy a local SIM at São Tomé airport when I land?
Do not plan on it. CST's own list of its twelve stores does not include the airport, and we could not confirm a working counter for either operator in the arrivals area. The Loja Central on Largo de Água Grande, opposite the cathedral, is a short taxi ride away and opens 07:30 to 19:00 seven days a week. Bring your passport, since both operators register numbers. If you land late or fly straight on to Príncipe, that is exactly the gap the Nomad eSIM fills.
What is mobile coverage like on Príncipe?
Usable in and around Santo António, the island's only real town, which also has a CST store. Beyond it, coverage thins quickly across the forested south and the bays near Roça Sundy, where Eddington photographed the 1919 eclipse that tested relativity. Many of the island's lodges are deliberately secluded and lean on their own WiFi. Ask yours which operator works on site before you choose between a CST card and the Nomad eSIM on Unitel.
Does internet ever go down across the whole country?
It can. International traffic depends on a very small number of submarine links, and Unitel's homepage currently warns of maintenance on its international circuits that would cut internet and international calls from 1am to noon over three days, while domestic calls and texts kept working. Power cuts are a separate and more frequent problem, since a mast without backup goes quiet with the grid. Holding lines on both networks, a CST card plus the Nomad eSIM, is the simplest hedge.
Will a regional Africa eSIM cover São Tomé as part of a bigger trip?
Do not assume so. Airalo and Holafly have no São Tomé product at all, and we found no regional bundle from either that names the country. Nomad is the only one of the three with a plan, and it is a single-country plan. If you are combining the islands with Gabon, Cameroon or Angola, sort the mainland legs separately and treat São Tomé as its own purchase, either Nomad before you fly or a CST card on arrival.