We built the eSIM layer the roaming industry refused to build — founded in Tallinn in 2019, now powering 412,000+ subscribers across 142 countries.

Founded by telecom engineers who refused to keep paying their own roaming bills.

In 2019, a small group of engineers from Skype and TransferWise met in Tallinn with a shared grievance: every trip outside the EU meant either a plastic SIM swap in a back-office kiosk, or a four-figure roaming bill waiting at the end of the month. They had spent a decade building voice and payment infrastructure at planetary scale. They knew the layer was technically solvable.

Teleki Blanka was the answer. The thesis was deliberately unfashionable: a contract-free, single-profile data layer that worked on any eSIM-capable handset, priced like infrastructure rather than like a holiday add-on. Six years later, the same engineering desk still ships every network release — now 64 people across six time zones, with the founding team still in the room.

• 01

  Engineering-first DNA

  Founders and 60% of staff are former infrastructure engineers from Skype, TransferWise, and Bolt — the company writes its own eUICC stack rather than reselling one.

• 02

  A connectivity layer, not a carrier

  Teleki Blanka is a reseller and eSIM provider with carrier-grade engineering depth, partnering with 27 tier-1 MNOs — including Vodafone, Orange, and NTT Docomo — for actual signal delivery.

• 03

  Built in Tallinn, shipped globally

  Headquartered on Tornimäe tn 5, with network operations distributed across Lisbon, Tbilisi, Singapore, and Mexico City. The NOC never sleeps; the median support response is 1m 47s.