Updated September 30, 2026 · TariffCue Editorial Team
KnowRoaming vs Simbye
What sets them apart
| Compare |  KnowRoaming |  Simbye |
|---|---|---|
| Price from | $1.75 | €1.95 |
| Reference plan prices | USA Unlimited 30 Days: US $68.00, unlimited data, prepaid 30 days (no 12-month 30 GB+ SIM-only plan offered); USA Unlimited 1 Day: US $3.50, unlimited data, prepaid 1 day; USA 1 GB 7 Days: US $3.89, 1 GB, prepaid 7 days | Japan 1 GB: EUR 1.95, 1 GB, 7 days, prepaid no contract (cheapest plan overall) | Japan Unlimited: EUR 18.95, unlimited, 7 days, prepaid no contract (cheapest unlimited) | Build Your Own eSIM, app only: 5-50 GB, 30-365 days validity, up to 10 countries (12-month, 30 GB+ line, price set in app) |
| Unlimited plan price | $3.50 | €18.95 |
| Roaming countries | from 200 | 190 |
| Host network | Not confirmed | NTT Docomo, KDDI/au, SoftBank, Rakuten Mobile (Japan); Orange Holiday Europe (Europe); 700+ partner networks worldwide |
| 5G | Not confirmed | Yes |
| EU roaming | Not confirmed | Included |
| Data rollover | Not confirmed | No |
| Hotspot sharing | Not confirmed | Yes |
| Markets | Not confirmed | CH, GB, PL, TR, US |
Same on both: Seller type (Reseller), SIM-only (Yes), eSIM (Yes).
We earn a commission when you sign up through links on this site. Partner status can affect where a brand appears in our rankings.
Key differences
- KnowRoaming scores higher overall: 9.1 vs 8.8.
- Support channels: only KnowRoaming offers Help centre.
- Support channels: only Simbye offers Chat, Email.
Our verdict on each
KnowRoaming
KnowRoaming sells prepaid sim-only eSIM data for travellers who want to buy a plan, use it and walk away, and the USA Unlimited daily plan at $3.50 makes a single heavy-use day cheap. Coverage spans from 200 countries, though the monthly unlimited option is where the range gets expensive.
Simbye
Simbye is a prepaid eSIM reseller that suits travellers who want a short single-market data plan instead of a long mobile contract. Its entry plan starts at €1.95, Japan eSIMs run on the major Japanese carriers, and help arrives by chat and email.
Score breakdown
| Area | KnowRoaming | Simbye |
|---|---|---|
| Cost | 9.5HigherEntry price of $1.75 and unlimited data at $3.50 put KnowRoaming near the front of both price measures. | 8.7The entry plan is €1.95 and the unlimited plan is €18.95, with EU roaming included across 190 countries. |
| Offer | 8.7Sim-only eSIM plans across from 200 countries, sold on prepaid billing by the day. | 8.9HigherEntry plan starts at €1.95, close to KnowRoaming at $1.75, while unlimited sits higher at €18.95. |
Positions in our rankings
| Ranking | KnowRoaming | Simbye |
|---|---|---|
| Phone plans with eSIM | 8 of 389 | 3 of 389 |
Licences and countries
| Country | KnowRoaming | Simbye |
|---|---|---|
| Headquarters | Not confirmed | United Kingdom |
What we checked
KnowRoaming
- knowroaming.com: 9 facts, checked September 30, 2026
Simbye
- simbye.com: 18 facts, checked September 30, 2026
Every fact side by side
| Fact | KnowRoaming | Simbye |
|---|---|---|
| Billing | Prepaid | Prepaid |
| Contract length | Not confirmed | 1, 12 |
| Legal entity | Not confirmed | Simbye Ltd |
| Headquarters | Not confirmed | United Kingdom |
| Support channels | Help centre | Chat, Email |
Where each stands against the rest
| Fact | KnowRoaming | Simbye | Median |
|---|---|---|---|
| Roaming countries | from 200highest quarter | 190highest quarter | 100 |
Median across 176 listed providers.
Pros and cons
KnowRoaming
Pros
- Both sim-only and eSIM are offered, so nothing is posted and no store visit is needed, which suits a traveller already carrying a compatible handset.
- Coverage of from 200 countries lets a multi-stop trip stay with a single provider instead of changing SIMs at each border.
- Billing is prepaid, so every purchase is a set figure with no renewal step and no minimum term to serve out.
Cons
- Support runs on help centre only, so a connection that fails overnight leaves a help centre to sort it out.
- KnowRoaming is a reseller rather than a mobile virtual network operator, so a network fault has to be traced through another party; co:sim and BambooSIM answer as their own operators.
- The monthly USA Unlimited option costs many times the entry figure of $1.75, so a full month of heavy use is the expensive end of the range.
Simbye
Pros
- The entry Japan plan starts at €1.95, close to KnowRoaming at $1.75.
- Roaming reaches 190 countries and EU roaming is included, so a multi-country trip needs no extra regional pack.
- Japan eSIMs ride NTT Docomo, KDDI/au, SoftBank and Rakuten Mobile, with hotspot sharing available on the same plans.
Cons
- Data rollover is not offered, so an unused allowance expires with the plan it was bought for.
- Support runs on chat and email, with no phone line among the listed channels, so a failed install has no voice route.
- Simbye is a reseller, and the carrier you connect to in Japan belongs to a partner rather than to Simbye itself.
Who each suits
KnowRoaming
Who it suits
- Travellers already holding a compatible handset who want data only, bought digitally with no delivery wait.
- Anyone covering a multi-country trip from a single provider, given coverage of from 200 countries.
- Readers who plan a trip day by day and want unlimited data for a single heavy-use moment rather than a capped monthly allowance.
Who should look elsewhere
- Readers who would rather deal with the network's own operation, since co:sim and BambooSIM run as mobile virtual network operators.
- Shoppers who want the lowest starting figure, since ESIMZON starts at $1 against KnowRoaming's $1.75.
Simbye
Who it suits
- Travellers landing in Japan who want data on a major Japanese carrier without taking a handset contract.
- People who want to buy and install an eSIM in the app before departure.
- Readers who want a small prepaid top-up for a single market rather than a monthly allowance.
Who should look elsewhere
- co:sim suits anyone who would rather buy from an MVNO, as co:sim is mvno, than from a reseller working on partner networks.
- KnowRoaming fits a reader whose budget is set in dollars, with an entry price of $1.75.
- ESIMZON suits anyone who wants its named partner set, from AT&T and T-Mobile to Verizon, rather than a Japanese carrier mix.
Questions about each
KnowRoaming
What does a KnowRoaming plan cost to start with?+
KnowRoaming's eSIM data plans start at $1.75, the entry figure for its lightest option. It is a set price rather than an introductory rate that renews higher, and billing is prepaid, so a reader can work out the whole spend for a trip before buying anything.
How much does unlimited data cost?+
The USA Unlimited daily plan is $3.50 for a full day of unlimited data, which is the figure most useful for anyone planning a trip day by day. The monthly unlimited option is priced far above that, so longer stays work out better with a smaller allowance topped up alongside it.
Simbye
What does the cheapest Simbye plan cost?+
The entry Japan plan starts at €1.95 as a prepaid plan with no contract, so you buy a set amount of data for a fixed trip rather than a monthly allowance. Unlimited data on the same Japanese coverage comes from the Japan Unlimited plan at €18.95. A Build Your Own eSIM can also be set in the app across several markets.
Is there an unlimited data option and what does it cost?+
The Japan Unlimited plan costs €18.95 and carries uncapped data for a short validity window, on 5G networks with hotspot sharing available. Compared with the entry plan at €1.95, the jump is large, so unlimited makes sense for a stretch of heavy use in Japan and less sense for a brief visit.