Privacy policy

Canada GST HST Tax Worksheets, a Google Sheets add-on by Hexloom Labs. Last updated October 2026.

In short

The add-on works inside the spreadsheet you open it in. What you type into your sheets is not sent to us or to anyone else. The only thing the add-on sends us is a licence key, and only if you have bought a plan.

What the add-on can access in Google

The add-on asks for two permissions: to view and manage the spreadsheet it is opened in (spreadsheets.currentonly), and to show its sidebar (script.container.ui). It cannot see your other spreadsheets, your Drive, your email or your contacts. It uses the first permission to add sheets and formulas (the rates sheet, the calculator and return worksheets) to the spreadsheet you are working in.

What is stored, and where

• If you enter a licence key, the add-on stores it, and a signed seven-day token that proves the plan was active, in Google's Apps Script user properties for your Google account. When you open the sidebar with a token less than two days from expiry, about once a week, the add-on sends the key to us again to renew the token. The sidebar has a "Remove my key from this account" button that deletes them.
• If you open the plan page and type your licence key, the key is sent to us, and we send it to Stripe to open its billing page for your subscription. We do not keep the key on that page. From the sidebar link, the key travels in the part of the address after the "#", which your browser does not send to any server, and the page removes it from the address bar once it is in the form.
• Nothing from your spreadsheets is stored by us.

What is sent to us

• Rates file. The sidebar downloads the rates file from hexloomlabs.com. The request carries no sheet data and no key.
• Licence check. If you have a key, the sidebar sends it to hexloomlabs.com so that our server can ask Stripe whether the subscription is active. The server answers yes or no and returns the signed token. The key identifies a Stripe subscription; it does not contain your name or email address.
• Server logs. Our hosting provider, Cloudflare, records standard request details such as IP address and browser type for security and abuse prevention, and provides aggregate traffic statistics without cookies. We do not keep or export these logs ourselves; Cloudflare retains them under its own policy.

Payments

Plans are sold through Stripe. Stripe collects your card and billing details and handles sales tax. We receive confirmation that a payment was made, the Stripe customer and subscription identifiers, and the email address and billing country you gave Stripe at checkout. We use the email only to answer your support requests about that plan. We keep no separate copy: it stays in our Stripe account, and we delete it on request unless the law requires us to keep payment records. We never see or store card details. Stripe's own privacy policy applies to the information you give it.

The web calculator and the launch email

The calculator at /gst-sheets/calculator/ works entirely in your browser: the amount you type is never sent to us. The page counts visits and calculator uses without recording what you entered, and Cloudflare web analytics counts page views. If you leave your email in the form on that page, Hexloom Labs stores it to send one confirmation message and, once you confirm, one more message when the add-on is listed. The confirmation is a separate mail from the launch mail. Every message has an unsubscribe link, and we do not sell or share the address.

What we do not do

• We do not read, copy or store the contents of your spreadsheets.
• We do not sell personal information, share it for advertising, or use it for advertising.
• We do not use data from Google services for anything other than providing the add-on's features to you. Canada GST HST Tax Worksheets' use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including its Limited Use requirements.

Contact and your choices

To ask what we hold about you, or to have it deleted, write to us through the support page. You can stop the add-on at any time by removing it from Google Workspace Marketplace settings and cancelling your plan on the plan page. The wider Hexloom Labs privacy policy covers our other products and the main site.

Changes

If this policy changes, the date at the top changes with it.