Privacy policy

Who we are

Taxmiser is operated by M3CA LTD ("we", "our", "us"), 35 Berkeley Square, Berkeley Suite, Mayfair, London, W1J 5BJ, United Kingdom. M3CA LTD is the controller of your personal information: it decides why and how it is processed. You can reach our privacy team at info@m3ca.com or on (+44) 20 3978 6347. Please mark any message "Privacy request" so it is routed to the team that handles access, correction and deletion.

M3CA also operates M3CA LLC in the United States, which is the controller for engagements contracted there. Taxmiser memberships are always contracted with M3CA LTD, so M3CA LTD is your controller wherever you live.

Last updated 12 September 2026.

What we keep

We keep the information you give us, such as your name, email address, account credentials, saved tax plans, filing progress, strategy notes, accountant briefs and support messages. We also keep technical information needed to run and protect the service: IP address, browser and device type, usage and clickstream data, and error logs. Payment card details are collected and processed by Paddle, our payment provider, and are not stored by Taxmiser.

Why we use it

We use your information to provide your account, calculate and save plans, process transactions and invoices, keep the service secure, detect and prevent fraud, improve features, answer support requests, send service notifications, and meet our legal duties. Our legal bases are performing our contract with you, legitimate interests, consent where we ask for it (for example optional cookies and marketing), and legal obligations such as tax and accounting record-keeping.

Who receives it

Information may be shared with trusted providers supporting hosting, analytics, email and customer service. They may access your information only to perform tasks on our behalf and must protect it to a standard at least equal to this policy. Information is shared with Paddle, who acts as the Merchant of Record for subscriptions, payments, tax, invoicing and billing support. It may also be shared with professional advisers and with authorities when the law requires it.

What we never do: we do not sell your personal information, we do not use your content to train third-party foundation models, and we do not share your data with advertisers for their own purposes.

Retention and security

We keep personal information only as long as necessary for the purposes it was collected for, or to meet legal obligations. Account data is kept while the account is active, then deleted or anonymised. Financial records are kept for the period required by tax and company law. We apply appropriate technical and organisational measures, including encryption in transit and at rest, access controls, least-privilege permissions, monitoring and logging. No method of internet transmission is fully secure, so we cannot guarantee absolute security. Where a personal data breach is likely to risk your rights and freedoms, we notify the relevant supervisory authority within 72 hours and affected individuals without undue delay.

Your choices and rights

You may ask to access, correct, delete, restrict or transfer your information, object to some uses (including direct marketing), or withdraw consent. You can also download your data and manage account closure from your account page. UK and EEA users may complain to the UK Information Commissioner's Office at ico.org.uk, or to their local supervisory authority. California residents have the rights described by the CCPA and CPRA, including the right to know, delete and correct; we do not sell or share personal information as those laws define it. To exercise any right, email info@m3ca.com marked "Privacy request". We aim to respond within one month and there is no charge for a reasonable request.

Cookies and international transfers

Cookies are small files stored on your device. We use four categories, the same as the wider M3CA cookie policy:

• Essential cookies, which keep your session, sign in and preferences working.
• Performance and analytics cookies, which tell us which pages are used and where errors happen.
• Functionality cookies, which remember choices such as your country and reading mode.
• Marketing cookies, which are only set if you agree to them.

You can clear or block cookies in your browser settings, though essential cookies are needed for signing in and saving a plan. Optional analytics or marketing tools, when used, ask for your choice first. Where information leaves the UK or EEA, we rely on recognised safeguards such as adequacy decisions, the UK International Data Transfer Addendum or standard contractual clauses, together with appropriate technical safeguards.

Changes to this policy

We may update this policy to reflect changes in our practices, our services or legal requirements. Changes are posted on this page, and material changes are notified by email or a prominent notice on our website. Please review it periodically.