How we treat what you tell us
Williams Maths is run by Joseph Williams in Castelldefels and Barcelona. This page says, in plain words, what happens to the details a family gives us.
What we collect
When you write to us on WhatsApp or fill in the sign-up form, we receive what you type: typically a parent's name, phone and email, a child's first name, age or school year, school, and the location and time you prefer. We ask for nothing more than we need to place a child in a circle and reach the parent.
Why
To answer you, to invite you to a workshop, to run the short placement assessment, and to organise the class a child joins. We do not sell, rent or share these details with anyone else, and we do not use them for advertising.
Children
We deal with parents and guardians, not with children directly. A child's answers to problems, when logged in our app, are visible only to that child, their own parent and Joseph. They are never shown to other families.
Where it lives and for how long
Messages stay in WhatsApp; form responses land in a Google spreadsheet; class records live in our own app on servers in the European Union. We keep a family's details while the child attends and for a reasonable period afterwards, then delete them. Ask and we delete them sooner.
Your rights
Under the GDPR and Spanish data-protection law you may ask what we hold about you, have it corrected or deleted, or object to its use. Write to us on WhatsApp at +34 661 342 183 and we will act within a month.
Last updated September 2026.