This Privacy Policy explains how the Deltaline add-in for Microsoft Excel ("the Add-in"), published by Bosau Digital LLC and made by Sven Bosau, operating Python & VBA at pythonandvba.com ("we", "us", or "our"), handles your data. It applies specifically to the Add-in. Our general website Privacy Policy continues to apply to your use of our website.

1. In Short

• The Add-in draws every chart locally, inside Microsoft Excel on your own device. The chart engine is bundled with the Add-in.
• Your worksheet data never leaves Excel. We do not receive, process, store, or have any access to your workbook contents.
• Like any add-in, the Add-in loads its program code from addins.pythonandvba.com and Microsoft's office.js. Beyond that, its only network request is checking a license key, and only when someone who has entered a key opens the chart editor, applies a chart, or adds the key. People who only open a workbook containing Deltaline charts make no license call.
• Each chart is a live chart in your workbook, linked to its data. What the chart needs (its settings and a snapshot image) is stored inside your workbook file and never contains a license key.
• Files you export (PNG images, HTML charts, dashboard pages) and share links you create contain the charted data by design; you decide where they go, and they are never sent to us.
• The Add-in contains no advertising, no cookies, no telemetry, and no third-party analytics or tracking.

2. Who We Are

The Add-in is published and operated by Bosau Digital LLC, the company behind Python & VBA (pythonandvba.com), founded by Sven Bosau. For any privacy-related questions, please contact us at contact@pythonandvba.com.

3. What Data the Add-in Processes

Your Spreadsheet Data

Everything the Add-in does (reading the range or table you link to a chart, following changes to it, drawing the chart, exporting files) happens locally, inside Excel, on your device. The Add-in reads only the data you use for a chart and draws it with the bundled chart engine. We do not receive, process, store, or have any access to your workbook contents.

The Add-in writes to your workbook cells in two cases only: when you start a chart from sample data, it writes a small sample table into empty cells of the sheet (or a new sheet when there is no room); when you type a comment on a chart, it writes that comment into the Comments column of the chart's data, or into a new Comments column next to it. It never changes the cells that hold your numbers.

Data Stored Inside Your Workbook

Each chart is an Office content add-in in your workbook. Microsoft Office stores the following in the file:

• The chart's settings: the chart type, which cells it is linked to, its options, titles and footnotes, and a small copy of the most recently drawn data, so the chart can appear before Excel has loaded the cells;
• A snapshot image of the chart.

None of this ever contains a license key. It travels with your workbook like any other workbook content: anyone you send the file to receives it together with the cells themselves. It is never sent to us.

Outputs You Create (Exports, Share Links, Dashboards)

Charts are only useful if they show your data, so outputs you deliberately create contain it:

• Exported files (PNG images, copied images, interactive HTML charts, dashboard pages) are generated on your device and saved or pasted where you choose. They include the charted values. HTML files carry the chart engine inside them, so opening one loads nothing from us or anyone else.
• Share links encode the chart's settings and charted values, compressed, in the link itself (the part after the #). This part of the link is never transmitted to our server: when someone opens the link, their browser loads our viewer page from addins.pythonandvba.com and rebuilds the chart locally. Treat a share link like the chart itself: anyone you give the link to can see the charted data.

All of these are created only when you trigger them, and none of them are sent to us.

License Validation Data

To confirm that you hold a valid license, the Add-in sends the following to our license server (api.pythonandvba.com) over an encrypted connection. It never sends any workbook content:

• Your license key;
• An anonymous installation identifier, a random value generated on your device. It contains no name, email, or hardware or device information, and is used only to enforce the device limit of your license;
• The Add-in version.

The check runs only on author actions: opening the chart editor, applying changes to a chart, and adding a license key. Opening, viewing or recalculating a workbook that contains Deltaline charts never triggers it, so people who only view your charts make no license call. If you never enter a license key, this request is never made. A record of your last successful check is stored on your device so licensed features keep working for a short offline grace period (currently 7 days) if the license server cannot be reached, and then re-verify once you are back online.

Loading the Add-in

Like every Office add-in, the Add-in loads its program code when a chart or the chart editor starts: the Deltaline code from our server addins.pythonandvba.com, and Microsoft's standard add-in library (office.js) from Microsoft. These are ordinary web requests for code. They carry no workbook content, and we do not use them to track you.

Data Stored Locally on Your Device

The following are saved only in the Add-in's local storage on your device (under keys that start with dl.): your license key, the anonymous installation identifier, the date of your first use (which anchors the 14-day free trial), the record of your last successful license check, your presets and last-used options per chart type, your brand colors, your dashboard collection (the charts you add to it, including their charted values), and a picture of each chart's last drawing, including its values and titles, so a chart shows at once when Excel reloads it. You can remove your license key in the Add-in at any time; the rest stays on your device until you remove the Add-in and clear its Office add-in storage.

Purchases

Licenses are bought on pythonandvba.com. The checkout is run by Pabbly, and payments are processed by Stripe or PayPal. Your license key is sent to you by email. We receive your name, email address, and order details from the checkout. We never see your full card details. This is covered in more detail by our general website Privacy Policy.

Data Handled by Microsoft Excel

The Add-in runs inside Microsoft Excel on Windows, Mac and the web. Microsoft's handling of your Office documents and account data is governed by Microsoft's own privacy terms. See the Microsoft Privacy Statement.

4. Third-Party Services

• Microsoft Excel / Microsoft 365: the host application in which the Add-in runs, and the source of office.js.
• Our license server (api.pythonandvba.com, operated by us): checks license keys as described in Section 3.
• Pabbly, Stripe and PayPal: checkout and payment processing when you buy a license.

No other third parties receive any data through the Add-in. We do not sell your personal data.

5. What the Add-in Does Not Do

• It does not include advertising, cookies, telemetry, or third-party analytics or tracking.
• It does not send your worksheet contents, charts, or dashboards to us or to anyone else.
• It does not send automatic error reports. Error messages are shown in the Add-in only; if you contact support, you can choose to copy the diagnostic details from the Add-in and include them yourself.
• It does not change the cells that hold your numbers; sample tables go into empty cells, and comments go into a Comments column.
• It does not access hardware identifiers, your contacts, Microsoft Graph, SharePoint, OneDrive, or files outside the workbook you are working in.

6. How We Use Data

• To validate and manage your license and enforce its device limit.
• To let licensed features keep working during a short offline grace period after a successful license check.
• To deliver your license key and handle purchases and support requests.

That is the complete list: the Add-in's charting features themselves require no data to be sent to us, and viewing a workbook with Deltaline charts sends us nothing.

7. Legal Basis for Processing (GDPR)

If you are located in the European Economic Area (EEA) or the United Kingdom, we process the limited license and purchase data described above under the following legal bases:

• Contract performance: Verifying your license and delivering your purchase so we can provide the licensed features.
• Legitimate interests: Enforcing license limits and preventing misuse of our software.

8. International Data Transfers

Bosau Digital LLC and our license server are located in the United States or process data there. If you use the Add-in from outside the United States, the license validation data described above is transferred to the United States. Your workbook contents are never transferred, because they never leave your device.

9. Data Retention

• License records: Retained for as long as necessary to support your license and comply with legal obligations.
• Locally stored keys, settings, presets, brand colors and dashboard collection: Remain on your device until you remove them or the Add-in.
• Chart information stored in your workbook (settings and snapshot images): Remains in the file until you delete the chart or the file; it is under your control like the rest of the workbook.
• Worksheet contents: Not retained, received, or seen by us at all.

10. Your Rights

If you are located in the EEA or UK, you have the following rights under GDPR in respect of the personal data we hold (essentially, your license record and your purchase details):

• Access: Request a copy of the data we hold about you
• Rectification: Request correction of inaccurate data
• Erasure: Request deletion of your data ("right to be forgotten")
• Restriction: Request that we limit how we use your data
• Portability: Request your data in a machine-readable format
• Objection: Object to processing based on legitimate interests

To exercise any of these rights, please contact us at contact@pythonandvba.com. We will respond within 30 days. Because your workbook data never reaches us, there is no workbook data of yours for us to return or delete.

11. Data Security

We take reasonable technical and organisational measures to protect your data against unauthorised access, loss, or disclosure. The Add-in's program code and the license check are transmitted over encrypted (HTTPS) connections. Everything else stays on your device, in your workbook, or in the files and links you choose to create and share.

12. Children's Privacy

The Add-in is not directed at children under the age of 16. We do not knowingly collect personal data from children.

13. Changes to This Policy

We may update this Privacy Policy from time to time. The "Last updated" date at the top of this page will reflect any changes. Continued use of the Add-in after changes are posted constitutes acceptance of the updated policy.

14. Contact

For any privacy-related questions or to exercise your rights, please contact:

Related documents: Deltaline Terms of Use · Deltaline Security and Architecture · Website Privacy Policy · Refund Policy · Terms & Conditions