Contact
A person answers.
Sentra is built in London by a small team. There is no ticket queue and no chatbot — email one of the addresses below and a human replies.
Anything about the app
Questions, feedback, an area that wants to be in the first cluster, or something that is broken. This is the fastest route.
Your data, formally
Access, correction, deletion, portability or an objection. Use the subject line “Data request”. We reply within one calendar month.
Responsible disclosure
Found a vulnerability? Tell us before you tell anyone else and we will work it with you. Same address, subject line “Security”.
Universities and data providers
Venues, community groups, accommodation providers, students’ unions and platform partners reviewing an API application — write to the general address and it reaches the founder.
- Registered company
- SQUARE3 Limited
trading as Sentra - Company number
- 16466339
Registered in England and Wales - Registered office
- 92 York Street
London, England, W1H 1QX
United Kingdom - Data controller
- SQUARE3 Limited is the data controller for the Service. See the privacy policy.
If we cannot resolve it
For anything about personal data, you can complain to the Information Commissioner’s Office, the UK’s data protection regulator, at ico.org.uk or on 0303 123 1113. We would rather you gave us a chance first, but the right is yours either way.
Not an emergency service
Sentra is an information service and a walking app. It is not an emergency service, not a security service, and not a substitute for your own judgement. For a crime in progress, a medical emergency or an immediate threat to life, call 999 — or 101 for non-emergencies. Do not email us instead.
What we will not ask you for
- Your password. Not by email, not ever.
- Payment details by email.
- Your location, outside the app’s own permission prompt.
If a message claiming to be from Sentra asks for any of those, it is not from us — forward it to mda@sentra.city.
Sentra isn’t open yet. If you’d like your area to be among the first, get in touch.