sms.to is a Cypriot platform for business SMS messaging, aimed at developers and companies. It offers an SMS API, an SMPP API, a Viber messaging API, a verification API for multi-factor authentication, and HLR and MNP lookups for checking numbers. A web platform also lets you send messages for bulk campaigns, notifications, reminders and marketing; according to the website, messages can also go via WhatsApp, Telegram, RCS and Viber. SDKs are available on GitHub. The service is consumed as a cloud platform and through APIs, and it is not open source.
The responsible company is Intergo Telecom Ltd, based in Paphos, Cyprus, and therefore within the European Union. Its privacy policy states that personal data is processed within the European Economic Area and/or in an area covered by an adequacy decision, without naming countries or hosting providers. The pages consulted do not name an owner or parent company. A European organisation would be wise to ask the provider for the exact processing locations and sub-processors.