Last updated: 24 March 2026
Cookie Policy
This Cookie Policy explains how TaxWhizz.ai Ltd ("TaxWhizz.ai", "we", "us", or "our") uses cookies and similar tracking technologies when you visit our AI-powered tax intelligence platform at taxwhizz.ai (the "Platform"). This policy should be read alongside our Privacy Policy.
TaxWhizz.ai Ltd is registered in England & Wales. We comply with the Privacy and Electronic Communications Regulations 2003 (PECR) and the UK General Data Protection Regulation (UK GDPR).
1. What Are Cookies
Cookies are small text files that are placed on your computer, smartphone, or other device when you visit a website. They are widely used to make websites work more efficiently, provide a better user experience, and give website operators information about how their site is being used.
Cookies can be "first-party" (set by the website you are visiting) or "third-party" (set by a different domain than the one you are visiting). They can also be "session" cookies (which expire when you close your browser) or "persistent" cookies (which remain on your device for a set period or until you delete them).
In addition to cookies, we may use other similar technologies such as:
- Local Storage: Data stored in your browser's local storage that persists beyond browser sessions
- Session Storage: Data stored temporarily for the duration of a page session
- Pixel Tags / Web Beacons: Small transparent images used to track user behaviour and conversions
When we refer to "cookies" in this policy, we include all similar technologies unless otherwise specified.
2. How We Use Cookies
We use cookies for the following purposes:
- Authentication & Security: To identify you when you log in, maintain your session, protect against cross-site request forgery (CSRF), and ensure the security of your account
- Preferences & Functionality: To remember your settings, preferences (such as theme, locale, and dashboard layout), and provide personalised features
- Performance & Analytics: To understand how visitors use our Platform, identify popular features, detect performance issues, and improve the user experience
- Essential Platform Operation: To enable core functionality such as page navigation, access to secure areas, and proper rendering of the Platform
We do not currently use cookies for advertising or marketing purposes. If this changes in the future, we will update this policy and seek your consent where required.
3. Types of Cookies We Use
3.1 Essential Cookies (Strictly Necessary)
These cookies are necessary for the Platform to function and cannot be switched off in our systems. They are usually set in response to actions you take, such as logging in, setting your privacy preferences, or filling in forms. Without these cookies, the Platform cannot operate properly.
Status: Always active. No consent required under PECR as they are strictly necessary for the service you have requested.
| Cookie | Purpose | Type | Duration |
|---|---|---|---|
| tw_session | Maintains your authenticated session after login | First-party | Session |
| tw_auth_token | JWT authentication token for secure API requests | First-party | 7 days |
| tw_refresh_token | Refresh token for seamless session renewal | First-party | 30 days |
| tw_csrf | Cross-site request forgery protection token | First-party | Session |
| tw_cookie_consent | Records your cookie consent preferences | First-party | 1 year |
3.2 Functional Cookies
These cookies enable enhanced functionality and personalisation. They may be set by us or by third-party providers whose services we have added to our pages. If you disable these cookies, some or all of these features may not function properly.
Status: Persistent. Consent requested.
| Cookie | Purpose | Type | Duration |
|---|---|---|---|
| tw_preferences | Stores your display preferences (theme, density, layout) | First-party | 1 year |
| tw_locale | Remembers your preferred language and regional settings | First-party | 1 year |
| tw_dashboard_layout | Preserves your customised dashboard panel arrangement | First-party | 1 year |
| tw_recent_calcs | Stores recent calculator selections for quick access | First-party | 90 days |
3.3 Analytics Cookies
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our Platform. They help us understand which pages are the most popular, which features are used most frequently, and how visitors navigate through the site. All information these cookies collect is aggregated and therefore anonymised.
Status: Persistent (maximum 2 years). Consent requested.
| Cookie | Purpose | Type | Duration |
|---|---|---|---|
| _ga | Google Analytics — distinguishes unique users by assigning a randomly generated number | Third-party | 2 years |
| _ga_[ID] | Google Analytics 4 — maintains session state across pages | Third-party | 2 years |
| _gid | Google Analytics — distinguishes unique users for the current day | Third-party | 24 hours |
| _gat | Google Analytics — throttles request rate to limit data collection | Third-party | 1 minute |
| mp_[token]_mixpanel | Mixpanel — tracks user interactions, feature usage, and conversion events | Third-party | 1 year |
3.4 Marketing Cookies
We do not currently use marketing or advertising cookies. Our Platform does not serve advertisements, and we do not track you across other websites for advertising purposes.
If we introduce marketing cookies in the future, we will update this Cookie Policy, notify you, and seek your explicit consent before setting any marketing cookies on your device.
4. Third-Party Cookies
Certain third-party services integrated into our Platform may set their own cookies. We do not control these cookies. The following third parties may set cookies when you use the Platform:
4.1 Stripe (Payment Processing)
When you make a payment or manage your subscription, Stripe may set cookies to process your transaction securely, detect and prevent fraud, and comply with payment card industry regulations.
| Cookie | Purpose | Duration |
|---|---|---|
| __stripe_mid | Fraud prevention — unique identifier for the device | 1 year |
| __stripe_sid | Fraud prevention — unique identifier for the browsing session | 30 minutes |
For more information, see Stripe's Cookie Policy.
4.2 Google (Authentication & Analytics)
If you sign in using Google OAuth, Google may set cookies related to the authentication process. Additionally, we use Google Analytics to understand how visitors interact with our Platform.
| Cookie | Purpose | Duration |
|---|---|---|
| g_state | Google Sign-In — tracks the state of the Google One Tap authentication prompt | Varies |
| g_csrf_token | Google Sign-In — CSRF protection during authentication | Session |
| _ga / _gid / _gat | Google Analytics — see Analytics Cookies section above for details | Varies (1 min – 2 years) |
For more information, see Google's Cookie Policy.
4.3 Anthropic (AI Processing)
Our AI-powered features are powered by Anthropic's Claude API. Anthropic's service is API-based, meaning communication occurs server-to-server. Anthropic does not set cookies on your device through your use of our Platform. Your data is processed via secure API calls from our backend servers to Anthropic's infrastructure.
5. Cookie Duration Table
The following comprehensive table lists all cookies that may be set on your device when using the Platform:
| Cookie Name | Provider | Purpose | Type | Duration |
|---|---|---|---|---|
| tw_session | TaxWhizz.ai | Session management | Essential | Session |
| tw_auth_token | TaxWhizz.ai | JWT authentication | Essential | 7 days |
| tw_refresh_token | TaxWhizz.ai | Session renewal | Essential | 30 days |
| tw_csrf | TaxWhizz.ai | CSRF protection | Essential | Session |
| tw_cookie_consent | TaxWhizz.ai | Consent preferences | Essential | 1 year |
| tw_preferences | TaxWhizz.ai | Display preferences | Functional | 1 year |
| tw_locale | TaxWhizz.ai | Language preferences | Functional | 1 year |
| tw_dashboard_layout | TaxWhizz.ai | Dashboard layout | Functional | 1 year |
| tw_recent_calcs | TaxWhizz.ai | Recent calculators | Functional | 90 days |
| _ga | User identification | Analytics | 2 years | |
| _ga_[ID] | Session state (GA4) | Analytics | 2 years | |
| _gid | Daily user identification | Analytics | 24 hours | |
| _gat | Request throttling | Analytics | 1 minute | |
| mp_[token]_mixpanel | Mixpanel | Feature analytics | Analytics | 1 year |
| __stripe_mid | Stripe | Fraud detection | Essential | 1 year |
| __stripe_sid | Stripe | Session fraud check | Essential | 30 minutes |
| g_state | OAuth state tracking | Essential | Varies | |
| g_csrf_token | OAuth CSRF protection | Essential | Session |
6. How to Manage Cookies
You can control and manage cookies in several ways. Please bear in mind that removing or blocking cookies may impact your user experience and some features of the Platform may no longer be fully accessible.
6.1 Cookie Consent Banner
When you first visit the Platform, you will be presented with a cookie consent banner that allows you to accept or reject non-essential cookies. You can change your preferences at any time through your account settings.
6.2 Browser Settings
Most web browsers allow you to manage cookies through their settings. Below are links to cookie management instructions for major browsers:
- Google Chrome: support.google.com/chrome/answer/95647
- Mozilla Firefox: support.mozilla.org/en-US/kb/cookies
- Apple Safari: support.apple.com/en-gb/guide/safari/sfri11471
- Microsoft Edge: support.microsoft.com/en-gb/microsoft-edge
6.3 Opt-Out Tools
You can also opt out of specific analytics services:
- Google Analytics Opt-out: tools.google.com/dlpage/gaoptout — Install the browser add-on to prevent Google Analytics from collecting data
- Mixpanel Opt-out: mixpanel.com/optout
7. Impact of Disabling Cookies
If you choose to block or delete cookies, some features of the Platform may be affected:
| Cookie Type Disabled | Impact |
|---|---|
| Essential cookies | You will be unable to log in, maintain a session, or use authenticated features. The Platform will be effectively unusable. |
| Functional cookies | Your preferences will not be saved between visits. You will need to re-select your theme, locale, and layout each time. |
| Analytics cookies | No impact on Platform functionality. We will have reduced ability to understand usage patterns and improve the Platform. |
| Third-party (Stripe) | Payment processing may be affected. Stripe's fraud detection may flag transactions, potentially causing payment failures. |
8. Do Not Track Signals
Some browsers include a "Do Not Track" (DNT) feature that sends a signal to websites you visit indicating that you do not wish to be tracked. There is currently no universally accepted standard for how to interpret DNT signals, and no industry consensus on what constitutes "tracking" in this context.
At present, TaxWhizz.ai does not respond to DNT signals. However, you can manage tracking through our cookie consent mechanism and the browser tools described above. We will review our approach to DNT signals as standards evolve.
9. Changes to This Cookie Policy
We may update this Cookie Policy from time to time to reflect changes in the cookies we use, changes in technology, or changes in applicable law. When we make material changes, we will:
- Update the "Last updated" date at the top of this page
- Notify you via a cookie consent banner or email where appropriate
- Reset your cookie consent preferences where material new categories of cookies are introduced
We encourage you to review this Cookie Policy periodically to stay informed about our use of cookies.
10. Contact
If you have any questions about this Cookie Policy or our use of cookies, please contact us:
Data Protection Officer
TaxWhizz.ai Ltd
Registered in England & Wales
Email: privacy@taxwhizz.ai
For general legal enquiries, please contact legal@taxwhizz.ai.