Yesim eSIM Review: Is the 15% WELCOMETOYESIM Promo Code Worth It for International Travellers?

Yesim is a consumer travel eSIM and virtual-number platform operated by Genesis Group AG, a Swiss company registered in Baar, Canton of Zug (CHE-135.623.633), co-founded in 2019 by Max Pankratov and Dmitri Verbovski and listed as a GSMA member. Rather than issuing physical SIM cards, Yesim delivers digital eSIM profiles through its web checkout and mobile apps (4.8 out of 5 across 29,662 ratings on Google Play and 4.7 out of 5 across 1,839 ratings on the UK App Store as of 9 November 2026).

For UK travellers whose post-Brexit mobile plans charge £2–£7 per day outside Europe — or where inclusive EU roaming stops at the Swiss, Turkish, US or Asian border — Yesim provides 30-day fixed-data bundles (1GB to 50GB) and 1-to-30-day unlimited-data plans across more than 200 destinations, using SwitchLess multi-operator profiles that switch automatically to the strongest partner network, alongside a free built-in VPN in the iOS and Android apps.

When you follow our Yesim partner link and enter the official promo code WELCOMETOYESIM published on Yesim's Loyalty Program page, your first eSIM plan is discounted by 15% at checkout. Yesim allows one promo code per order: because the device-compatibility page offers a smaller 10% code (compdevices10) and buying two or more eSIMs triggers an automatic 10% multi-item discount, WELCOMETOYESIM (15% off) is the higher option for your first purchase.

Alongside the upfront discount, Yesim runs an internal reward currency called Ycoins, pegged at 100 Ycoins = €1.00 (or $1.00 USD). Every time you pay for an eSIM or top-up by credit/debit card, Apple Pay or Google Pay, Yesim credits 5% of the purchase price back in Ycoins to your account wallet. Booking travel services through links inside the Yesim app also returns 4% to 10% in Ycoins (5% on Trip.com, 6% on GetYourGuide, 4% on Discover Cars and 10% on Kiwitaxi).

Yesim displays prices in USD, EUR or GBP depending on your storefront selector; on 9 November 2026 the official USD web catalogue prices after applying WELCOMETOYESIM (15% off) work out as follows. For the United States (AT&T / T-Mobile / Verizon 5G), 5GB / 30 days drops from $10.80 to $9.18 (~£7.20), 10GB / 30 days drops from $16.80 to $14.28 (~£11.20), 20GB / 30 days drops from $25.20 to $21.42, and 7-day Unlimited drops from $25.20 to $21.42. For Thailand (AIS / DTAC 5G), 5GB / 30 days drops from $8.40 to $7.14 (~£5.60) and 10GB / 30 days drops from $13.20 to $11.22 (~£8.80).

For Japan (NTT Docomo / SoftBank 5G), 5GB / 30 days drops from $10.56 to $8.98 (~£7.05) and 10GB / 30 days drops from $19.20 to $16.32 (~£12.80). For Mainland China (China Mobile / China Unicom 5G, bypassing firewall restrictions without a separate VPN), 5GB / 30 days drops from $13.20 to $11.22 and 10GB / 30 days drops from $22.32 to $18.97. For the United Kingdom (O2 / Vodafone / Three / EE 5G, useful for inbound visitors or backup data), 5GB / 30 days drops from $11.52 to $9.79 and 10GB / 30 days drops from $19.20 to $16.32.

If you cross several borders in a year, Yesim's reusable Global Pay & Fly eSIM covers 170+ countries on a single eSIM profile and bills per megabyte used from your Ycoins balance (starting from $1.10/GB, with wallet top-up presets at $18, $42 and $90). Under Section 5.4.2 of the Terms of Service, your Pay & Fly and Ycoins balance does not expire as long as you open the Yesim mobile app at least once every 180 days.

For heavy data users, the 365-day Annual Global Unlim Day Pass covers 83 countries in 7-day ($40.80, or $34.68 with 15% off), 15-day ($58.80, or $49.98), 30-day ($100.80, or $85.68) or 60-day ($178.80, or $151.98) bundles valid for a full year, and any unused days roll over for another 365 days if you buy a fresh pass before expiry.

We reviewed Yesim's Terms of Service (effective 15 June 2026) and Refund Policy line by line. Unactivated data plans and top-ups can be refunded within 30 days of purchase, and installing an eSIM on your phone counts as activating it. Crucially, Section 7.4 states that any refund of €10 or less is credited exclusively in Ycoins — only refunds above €10 can return to your original payment method. If you hit a technical failure abroad, Section 7.2 requires you to contact [email protected] with screenshots within 1 hour of the issue.

Watch two billing clauses as well: Sections 6.7.2 and 8.6 state that adding a bank card to your profile or redeeming promotional Ycoins triggers a €0.50 verification charge, which Yesim refunds immediately as 50 Ycoins inside your app wallet rather than reversing to your bank account. And under Section 6.7.3, if you toggle on Auto-Top-Up, Yesim automatically repeats your previous plan purchase when your data balance drops below 30% or 1 day before expiry — leave Auto-Top-Up switched off unless you genuinely want automatic renewals.

Before buying any plan, check Yesim's compatible-devices list or dial *#06# on your phone to confirm an EID number appears (note that dual-physical-SIM iPhones sold in Hong Kong, Macau and Mainland China lack eSIM hardware). While most destination plans can be bought ahead of time and activated within 180 days, fixed-data plans for Japan carry a stricter 90-day activation window, cannot be topped up once exhausted, and must be installed after you arrive in Japan.

Standard Yesim eSIMs are data-only. If you need a separate number for calls or SMS, Yesim sells optional $7.20/month virtual numbers (UK, US, NL, CA) inside the app. However, Section 5.5 of the Terms notes that these are VoIP numbers: they cannot call emergency services (999/112/911), do not promise that every bank or messenger will accept VoIP numbers for SMS OTP, may require KYC identity checks, and carry a €1,000 penalty under Section 5.5.1(b) for spam or fraudulent use.

Compared with other travel eSIMs on BonusRoam, Saily (10% referral discount) or Airalo ($3 off for new users) can sometimes edge out Yesim by $1–$2 on headline single-country 1GB–5GB packs, while GigSky specialises in cruise-ship and inflight connectivity.

Yesim pulls ahead when you stack the 15% WELCOMETOYESIM first-order discount with 5% Ycoins card cashback on 10GB–30GB bundles, when you want a single 170+ country Pay & Fly eSIM whose balance does not expire after 7 or 30 days, or when you want the free built-in VPN included in the app. Skip Yesim if your phone lacks eSIM hardware or if you want a no-questions-asked cash refund to your bank card on a sub-€10 test plan.