Data deletion

Last updated: August 24, 2026

Historian ApS operates the Historian platform and this website. This page explains how to have data deleted, what we delete, where it is stored, and how long it takes. It is the practical companion to our Privacy Policy.

Who this applies to

Data we process for our customers. When a customer connects their website and their advertising accounts to Historian, we process that data on their behalf: the customer is the data controller and Historian is the data processor. Our processing terms are part of the customer agreement.

If you are a visitor to one of our customers' websites and want data about you deleted, please contact the operator of that website — it is their decision, and we act on their instruction. You are welcome to write to us as well, and we will pass the request on.

Visitors to historian.ai. For this website we are the data controller. Write to us directly.

How to request deletion

Email contact@historian.ai with the subject "Data deletion request".

Please include:

  • the website (domain) the request concerns;
  • the advertising account it concerns, if any — for example the Google Ads customer ID or the Meta ad account ID;
  • whether you want everything deleted, or only the data from a specific advertising platform;
  • a name and an email address we can reply to, so we can confirm that you are entitled to make the request.

We reply to confirm that we have received the request, and again once the deletion has been carried out.

Deletion at Historian is carried out manually by us. There is no self-service delete button in the product today. We would rather tell you that plainly than point you at a button that does not exist — the address above is a real inbox, and a real person answers it.

What we delete, and where it is stored

Data is held in two places — our SQL databases and our Azure Blob Storage — and we delete from both. Deleting only the database rows would leave files behind, so both are part of every deletion.

For each advertising platform a customer connects (Google Ads, Meta), we hold:

  • the account structure: campaigns, ad groups, ads including their ad text, keywords, asset groups and their assets;
  • ad creatives we have downloaded and stored as image files — advertising images and YouTube video thumbnails — kept as individual files in blob storage;
  • daily performance figures per ad group: impressions, clicks, spend, conversions and conversion value;
  • click identifiers (gclid) provided by the advertising platform, and the mappings that connect a click to an ad, a keyword, a campaign and a date;
  • the raw daily snapshot of the advertising account, stored as one JSON file per connected website per day in blob storage;
  • the access credentials (OAuth tokens) stored for the connection.

For the customer's own website we also hold the data described in the Privacy Policy — including page views, clicks and session statistics, and the captured page snapshots. Click identifiers from advertising (gclid, fbclid) are picked up here as well, on the customer's own website, and used to attribute a visit to the advertisement it came from.

A deletion request covers all of it, unless you ask us to limit it to one platform.

Copies may remain in routine system backups for a limited period, until those backups expire in their normal rotation. They are not used to restore deleted data.

How long it takes

We keep customer data, including advertising data, for as long as the customer relationship lasts. The history is the product: we do not delete it on a rolling schedule, and we prefer to say so plainly rather than state a shorter period than we keep.

We delete customer data within 30 days:

  • when the customer relationship ends;
  • when the customer, or a data subject through the customer, asks us to delete it;
  • when an advertising connection is disconnected — even if the customer relationship continues. Withdrawn consent means the platform data goes.

Deletion covers both places the data is held: our databases and our file storage, including the raw daily snapshots and the ad creatives we have downloaded.

Reconnecting does not restore the history. We build the record of a customer's advertising day by day, as we capture it. Where an advertising platform still makes past figures available, we may retrieve those figures again — but the detailed history we keep, including how the advertising account changed over time and the click-level attribution, starts again from the day of reconnection. That is a real cost of disconnecting, and we state it here so that it is not a surprise.

Disconnecting an advertising connection

If you only want us to stop collecting, you can disconnect the advertising account yourself.

Where the Google Ads integration page is enabled for your Historian account, an account owner or administrator can open Integrations → Google Ads and click Disconnect. That removes the access credentials we hold and stops any further collection. You can also revoke Historian's access from your own account with the platform — under third-party access in your Google Account, or under Business settings in Meta Business Manager.

Disconnecting stops collection. It does not by itself delete what has already been collected. To have that deleted as well, email contact@historian.ai — we delete it within 30 days, as described above.

Contact

Historian ApS
Strandvejen 157 1 th
2900 Hellerup
Denmark
contact@historian.ai
+45 26 37 79 13