Compliance & Trust
Data Residency
Data Controller
Attomus Limited is the data controller for SemaFore under UK GDPR.
Organisation Details
- Legal Name: Attomus Limited
- Registered in: England and Wales
- Company Number: 06517654
- Address: 23 Berkeley Square, Mayfair, London W1J 6HE
- Contact: hello@attomus.com
- ICO Registration: ZA718457
Core residency position
SemaFore is built so that core service data stays inside the Attomus boundary except for the narrowly scoped platform functions listed below. This page describes the product runtime; the privacy notice separately covers the public website, support intake, and related processors.
Our server infrastructure runs from Attomus-operated facilities in Coventry, United Kingdom. The databases that hold account information, organisation membership, audit events, and encrypted message ciphertext are operated under Attomus control in the UK.
What stays inside the Attomus boundary
- account identifiers such as phone number and display name
- organisation and membership records
- audit log entries
- encrypted message ciphertext
- encrypted file ciphertext
Mobile messages and files are encrypted on-device before transmission. Portal-admin broadcasts follow a separate path: the administrator’s browser fetches recipient-device key bundles through the portal and creates a distinct encrypted envelope for each device. The portal server rejects plaintext message fields, so only ciphertext envelopes cross the Cloudflare-hosted portal boundary and reach the core messaging server. The core server stores and routes ciphertext only and has no mechanism to read message content.
Narrow exceptions outside the Attomus boundary
The product runtime uses the following narrowly scoped external functions:
| Service | Role | Data processed |
|---|---|---|
| Apple APNs | iOS push delivery | Device push token and routing identifiers only; no decrypted message content |
| Google Firebase Cloud Messaging | Android push delivery | Device push token and routing identifiers only; no decrypted message content |
| Twilio | SMS OTP delivery | Phone number and OTP SMS body for sign-in delivery |
| Mailgun EU | Transactional email delivery | Recipient email address, email body, and delivery metadata for evaluation, account, invitation, approval, portal-login, and security messages; no SemaFore message or file content |
| Stripe | Paid-plan billing | Billing identity and payment data for paid organisations |
| Cloudflare Pages, Workers, and edge | Public-site and portal hosting, TLS termination, DDoS protection, and portal-admin request routing | Network metadata; portal session and administrative request data; ciphertext broadcast envelopes. Broadcast plaintext is encrypted in the administrator’s browser and rejected by the portal server boundary |
Outside these functions, personal data does not leave the United Kingdom and does not leave Attomus.
Email and analytics
SemaFore sends transactional email through Mailgun’s EU service for evaluation and account setup, organisation invitations and approval requests, portal-admin login codes, and security notifications where those functions apply. SemaFore does not use third-party advertising, behavioural tracking, or data-broker services. The privacy notice describes the provider boundaries in detail.
Privacy Policy and Data Rights
- Privacy Policy: https://semafore.io/privacy
- Data Subject Rights: Contact hello@attomus.com with subject line “Data Rights — SemaFore” to request access, rectification, erasure, restriction, portability, or objection. Attomus will respond within 30 days.
- ICO Complaints: Users may lodge complaints with the Information Commissioner’s Office at ico.org.uk.