Rethinking financial services that benefits everyone

i25s is deeply engaged in developing applications and systems for the good of the many. We do so by bridging the current systems with new decentralized monetary systems – first and foremost by building Tagion.

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Our Services

Customer Engagement Services

An iOS and Android allowing stores to offer their customers discounts, to provide feedback, two-way communication, and to gather loyalty points. The app will soon enable store owners to accept payments in fiat (credit cards) and in selected cryptocurrencies.

Secure Wallet

Be your own bank. I25S is creating the first commercial app on top of Tagion. With the wallet, you can store, transfer, and manage your assets with the swipe of a finger

Decentralized key backup

A grief with online wallets, is that all is lost, in case the keys are lost. Not anymore. Soon, i25s offers a decentralized solution for making backup of key-pairs that can only be retrieved you its rightful owner.

About I25S

Strategic IT and FinTech consultants

Strategic IT and FinTech consultants

I25S is a trusted partner of two Danish C20 companies and a wide range of other clients.


With headquarters in Denmark, a development hub in Ukraine, and a wide range of consultants spread all over the world, we cover the needs of both national and international clients.

The company behind Tagion

i25s is the founding company behind the international open-source project, Tagion (


Tagion is a banking system that has the capacity to grow beyond what is possible today, with the existing financial systems.


Tagion provides a stable currency, close-to-zero transfer fees, a foundation for positive interest rates, and for competitive and transparent loan markets to everyone everywhere.

Theis Simonsen, CEO

Experienced strategist, developer, lecturer, and executive. Prior to i25s, Theis served as a senior consultant at KPMG and an external lecturer at Copenhagen Business School. M.S. in Information Technology from I.T. University of Copenhagen.


Kristian Vestergaard, CCO

20+ years of experience as a business and enterprise architect. Leader experiences from various positions, last as a Director of Digital Architecture at GN Audio A/S, where he also served on the Board of Directors.​


Carsten Rasmussen, CTO

Low-level architecture and core network concepts. Before Tagion, co-founded Polaric Semiconductor as a CTO, leading team that was engineering NFC and Bluetooth chips.


Huginsvej 2B, 3400 Hilleroed, Denmark