Privacy policy
How we handle personal data when you use the SCR Calculator website, your account and the app's licence service. Last updated 1 November 2026.
1. Who we are
SCR Calculator is made by SmallTrade Limited, a company registered in England and Wales with company number 08492769 ("we", "us"). We are the controller of the personal data described here. You can reach us at support@scrcalculator.com.
This policy covers the website www.scrcalculator.com, the account pages on it, and the licence service that the SCR Calculator app, its command line and its Python package use when you sign in.
2. What we hold
Your Microsoft account
You sign in with a Microsoft account. Microsoft tells us your account's identifiers (the tenant id of your organisation's Microsoft directory, or of Microsoft's personal accounts, and the object id of your account), your name, your email address or user name, and, through your tenant or email domain, which organisation you belong to. We never see or store your password.
Your devices
To apply the device limit of your licence, the app sends an identifier of your computer. It is a one-way hash of the computer's machine id, so the machine id itself never leaves your computer and cannot be worked out from what we store. The app also sends the name of the computer, which we show on your account page so you can recognise it.
Sign-ins and licence requests
Each time you sign in to the website or the app asks for a licence, we record the time, your IP address, the product (app, command line or Python) and its version, the device, the licence plan given and the result.
Licences and invoices
For paid licences we hold the organisation's name, contact names, email addresses and telephone numbers, billing address, the licence terms, the seats and who they are assigned to, invoice references and payment status.
Academic applications
If you apply for an academic licence, we hold what you tell us: your institution, department and role, the course or research you describe, your university email address, your declaration, and our decision.
Version 1
Version 1 of the app sent details of the computer's hardware (such as its processor and BIOS) when you signed in. Version 2 does not collect hardware details.
3. What we do not hold
- Your portfolio data. All calculations run on your own computer. Your holdings, market data, results and workbooks are never sent to us.
- Passwords. Sign-in is handled by Microsoft.
- Payment card details. Licences are paid by bank transfer.
- Analytics, advertising or tracking data. The website uses no tracking cookies and no analytics services.
4. Why we use it, and our lawful bases
| Purpose | Lawful basis (UK GDPR) |
|---|---|
| Licensing: checking your sign-in, deciding your plan, issuing licences, applying device limits, managing seats and organisation licences | Performance of a contract with you or your organisation, or steps you ask for before one (evaluations); our legitimate interest in licensing our software |
| Security: rate limits, sign-in records, detecting misuse, blocking accounts | Our legitimate interest in protecting the service and our software |
| Billing: quotations, invoices, payment records | Performance of a contract; legal obligation to keep accounting records |
| Support: answering your questions, looking into problems with your account | Performance of a contract; our legitimate interest in helping our users |
| Academic applications: checking that you qualify | Our legitimate interest in offering free academic licences to those who qualify |
If your organisation holds your licence, its licence administrators can see your name, email address, seat and when your organisation's members last signed in, so they can manage the licence.
5. How long we keep it
- Sign-in and licence request records: 12 months.
- Account data (identifiers, name, email, devices, academic applications): while you have a licence or evaluation, and for 2 years after it ends.
- Billing records: 6 years after the end of the financial year they relate to, as accounting law requires.
6. Who else handles it
- Our hosting provider runs the server and database of the website, as our processor, under a contract that lets it use the data only to provide the service to us.
- Microsoft provides the sign-in. Microsoft handles your account under its own privacy statement; we receive only what it sends us when you sign in.
- Your organisation's licence administrators, for licences your organisation holds, as described above.
We do not sell personal data and do not share it for advertising. We disclose it to others only if the law requires us to.
7. International transfers
If personal data is handled outside the United Kingdom, we make sure it is protected to the standard UK law requires: either the country is covered by UK adequacy regulations, or the transfer is made under the UK International Data Transfer Agreement or the UK addendum to the EU standard contractual clauses. Microsoft's sign-in service operates worldwide under Microsoft's own transfer safeguards.
8. Your rights
You have the right to ask for a copy of your personal data (access), to have it corrected (rectification) or deleted (erasure), to restrict or object to how we use it, and to receive it in a portable form (portability). Write to us at the address below; we answer within one month. Some rights depend on the lawful basis, and we may need to keep billing records for legal reasons.
If you are unhappy with how we handle your data, you can complain to the Information Commissioner's Office (ico.org.uk, telephone 0303 123 1113). We would appreciate the chance to put things right first.
9. Cookies
The website sets one cookie, and only when you sign in: a session cookie that keeps you signed in. It is strictly necessary, is deleted when you close your browser or sign out, and expires after 8 hours without activity. There are no analytics, advertising or tracking cookies, so there is no cookie banner.
10. Security
The website is served over an encrypted connection. Licences are digitally signed, device identifiers are stored only as one-way hashes, and access to the administration of the service is limited to us.
11. Contact
For anything about this policy or your data, write to support@scrcalculator.com.
12. Changes to this policy
We will update this policy when what we do changes, and show the date of the last change at the top. If a change matters to how your data is used, we will also say so on the website.