1. Who we are
SQUARE3 Limited (referred to as "Sentra", "we", "us") is the data controller for personal data processed in connection with the Sentra app and the website at sentra.city (the "Service").
- Registered office: 92 York Street, London, England, W1H 1QX
- Company number: 16466339
- General privacy enquiries: legal@sentra.city
2. Our privacy promises
Sentra is built on privacy by design and by default (Article 25 UK GDPR). Specifically:
- Anonymous by default. You can view safety information without an Account.
- We aim to host personal data primarily in the UK, although some service providers may process limited data outside the UK as explained below.
- Data minimisation. We collect only what is necessary for the feature you are using.
- We retain report data only for as long as necessary, generally up to 90 days unless longer retention is required.
- Industry-standard encryption and security measures.
- We do not sell your personal data.
3. What data we collect, why, and on what lawful basis
3.1 Account creation and verification
| What we collect | Why we need it | How long we keep |
|---|---|---|
| Email, display name, password | To create and manage your account | Until your account is deleted, plus a short period for system backup/deletion |
| Phone number (optional) | To help secure your account with verification features | Until removed |
If identity verification is used, this is handled by our third-party verification provider under their own privacy terms.
3.2 Location data
| What we collect | Why we need it | How long we keep it |
|---|---|---|
| Approximate location | To show relevant nearby safety information | Usually only while the app is in use |
| Precise location (if you enable it) | To support features such as reporting incidents, route planning or alerts | Only as needed for the relevant feature |
| Location sharing data (if enabled) | To allow optional family or shared safety features | Until you turn the feature off |
You control location permissions through your device settings and can switch them off at any time.
3.3 Reports and other user-generated content
| What we collect | Why we need it | How long we keep it |
|---|---|---|
| Information you submit in a report (such as report details, time, location and optional images) | To display reports, improve safety insights and operate the Service | Usually up to 90 days, after which identifiable report data is deleted |
| Verification status linked to your report | Same retention period as the report |
We may keep anonymised statistics after deletion so we can identify broader safety trends.
3.4 Device, app, and analytics data
| What we collect | Why we need it | How long we keep it |
|---|---|---|
| Device information, IP address, app version and technical usage data | To keep the app secure, diagnose issues and improve performance | Short retention periods unless aggregated |
| Crash/error reports | Limited retention | |
| Usage analytics | Aggregated or retained only as needed |
We do not use third-party advertising trackers, Meta Pixel, or cross-site/cross-app tracking SDKs. There is no advertising-ID-based profiling.
3.5 Communications
| What we collect | Why we need it | How long we keep it |
|---|---|---|
| Messages you send to support | To respond to your enquiry and support your account | As needed for support and record-keeping |
| Marketing preferences (if you opt in) | To send updates and product communications | Until you unsubscribe |
We will only send you marketing if you have specifically opted in (PECR / soft-opt-in). Every marketing email contains a one-click unsubscribe.
3.6 Aggregated and anonymised data
We may use anonymised and aggregated data for analytics, service improvement and business reporting. This data does not identify individual users.
4. Special category data
We do not intentionally collect special-category data (health, ethnicity, sexual orientation, religion, political views, trade-union membership, biometric or genetic data).
If you submit a Report that incidentally includes special-category data (e.g. a hate-crime report describing the victim's ethnicity), our moderation policy is either to redact the identifying details before display, or to ask you to resubmit the Report without those identifiers and delete the preceding Report.
5. Who we share data with
We share personal data only with the parties listed below, and only for the purposes described.
5.1 Sub-processors (act on our instructions)
| Sub-processor | Purpose | Location |
|---|---|---|
| Amazon Web Services (AWS) UK | Hosting, storage, compute | UK (London region) |
| Mapbox | Map tiles, geocoding, routing | EU/US |
5.2 Third-party data sources (not your data going out — their data coming in)
The Service does not currently ingest data from third-party data sources. If this changes in future (for example, if we integrate a public-sector data feed), this Policy will be updated and any new sub-processors added to the list in section 5.1.
5.3 Disclosures to law enforcement
We may disclose personal data where required by law or where necessary to protect users or others from harm.
5.4 Corporate transactions
If Sentra is involved in a merger, acquisition, financing round, or sale of assets, your personal data may be transferred to the counterparty subject to confidentiality obligations and the same protections as this Policy. We will notify users of any change in controller.
5.5 We do NOT
- sell your personal data;
- share it with advertising networks for profiling or behavioural advertising;
- use it to train third-party AI models.
6. Advertising
If advertising features are introduced in future, this Policy will be updated accordingly, and we will obtain your consent under PECR before introducing any advertising that uses cookies or device identifiers for tracking purposes.
7. Your rights under UK GDPR
You have the following rights, exercisable free of charge in most cases:
- Access — request a copy of the personal data we hold about you
- Rectification — correct inaccurate data
- Erasure / "right to be forgotten" — delete your data, subject to legal retention requirements
- Restriction — limit how we process your data
- Portability — receive your data in a structured, machine-readable format
- Object — object to processing based on legitimate interest, including profiling
- Withdraw consent — at any time, where we rely on consent. Withdrawal does not affect the lawfulness of processing before withdrawal.
- Right not to be subject to automated decision-making, where it produces legal or similarly significant effects on you. We will provide human review on request.
- Complaint to the ICO — as shown below in Clause 15.
To exercise any right, use in-app Settings → Privacy → Data Rights, or email legal@sentra.city with the subject line "Data Subject Request". We will respond within one calendar month (extendable by two further months for complex requests, with notification). We may need to verify your identity before responding, especially for access and erasure requests.
8. International transfers
Personal data is stored in the UK by default. Some sub-processors (Google, etc.) may transfer data to the EEA, US, or other jurisdictions for technical reasons (e.g. global CDN nodes). Where personal data is transferred outside the UK, we implement appropriate legal safeguards.
9. Retention
We retain personal data only as long as necessary:
- Account data: while your Account is open, plus 30 days for safe deletion.
- Reports: 90 days as raw data, then auto-deleted; aggregated/anonymised statistics may persist indefinitely.
- Billing and tax records: 6 years (HMRC requirement).
- Legal holds: if data is subject to a court order or active dispute, we retain it until the matter is resolved.
- Marketing consents: until you opt out.
- Logs: 30 days (security/access logs).
When the retention period ends, data is securely deleted or genuinely anonymised.
10. Security
Our technical and organisational measures include:
- Encryption: AES-256 at rest, TLS 1.2+ in transit.
- Access controls: role-based access, multi-factor authentication for staff, least-privilege.
- Hosting: UK regions only by default.
- Network security: WAF, DDoS protection, intrusion detection.
- Vulnerability management: dependency scanning, regular penetration tests, and a responsible disclosure programme at legal@sentra.city.
- Staff training: mandatory privacy training for all staff with access to personal data.
- Incident response: documented breach response plan with 72-hour ICO notification for personal-data breaches likely to result in risk to users (Article 33 UK GDPR).
- DPIA: completed before launch and reviewed annually, plus on any material change.
No system is 100% secure. We will notify you and the ICO of a personal-data breach in line with our legal obligations.
11. Children
The Service is not directed at children. If you believe an individual under 18 has used the Service, contact legal@sentra.city and we will delete the account and associated data.
12. Cookies and similar technologies
The Sentra app does not use tracking, analytical, or third-party cookies, pixels, or tags. We may use strictly necessary functional cookies or similar device storage (for example, for session continuity, security, and core app functionality). These are exempt from the consent requirement under regulation 6(4) of the Privacy and Electronic Communications Regulations 2003 (PECR). If a Sentra website is launched in future, this Policy will be updated and any optional cookies will require your consent.
13. Anonymous mode — what we do and don't see
When you use Sentra in anonymous mode (no Account):
- We do not collect: your email, name, payment data, or any data linked to a stable identity.
- We do see: device type, app version, IP address (for security and abuse prevention only — not retained against an identity), and approximate location while the app is in use.
- We do not combine anonymous-mode session data with Account data.
14. Changes to this Policy
We may update this Policy. The Last updated date at the top will always reflect the current version.
15. Contact
- Privacy: legal@sentra.city
- Postal: 92 York Street, London, England, W1H 1QX
If you have a complaint that we cannot resolve, you have the right to lodge it with the Information Commissioner's Office (ICO): ico.org.uk or call 0303 123 1113.