How to serve a construction lien notice to a contractor — and autofill cla-1 with my-id.ca
Preserve lien rights with Form 1 without retyping owner and contractor details
Owners, subcontractors, and suppliers preserving lien rights under the Construction Act repeat their legal name, project address, contractor identity, and contract details on every Form 1 notice to a contractor. This guide is an example of storing them once in my-id.ca.
Official form and source
Start from the official source and always use the current version — form numbers and links can change:
- Service page: Construction Act — ontario.ca
- Form (Central Forms Repository): Form 1 - Notice to Contractor Under Section 18 of the Act Construction Lien Act — cla-1
What this form is about
Form cla-1 is Form 1 — Notice to Contractor under section 18 of the Construction Act (formerly the Construction Lien Act), used in the lien preservation process on improvement projects — confirm deadlines and service rules on ontario.ca.
Before you start: what to gather
- Claimant's full legal name and business address.
- Contractor's legal name and address.
- Project or premises address and improvement description.
- Contract date and amount owing or disputed — confirm statutory particulars.
Confirm the current process on ontario.ca.
How my-id.ca makes it faster
- Save it once. Store your claimant and contractor names, addresses, and project location in your my-id.ca profile.
- Keep documents ready. Upload supporting documents to my-id.ca Files so you are not searching at form time.
- Autofill the form. Use the my-id.ca Chrome extension on a web form, or fill a PDF from your saved profile inside my-id.ca.
- Review and submit yourself through the official channel.
Why do it in my-id.ca
Related Ontario forms repeat the same personal details. Captured once in my-id.ca — stored in Canada, with AI on its own servers — every form starts mostly complete.
Frequently asked questions
- What is the deadline to preserve a lien?
- Confirm preservation timelines under the Construction Act on ontario.ca.
- How does my-id.ca help?
- It autofills business names and addresses across Construction Act forms.
- Must a lawyer prepare Form 1?
- Many claimants use legal help for lien disputes — confirm requirements for your situation.
Fill it once. Reuse it everywhere.
Save your information in my-id.ca once, then autofill this form and the next one — web forms with the Chrome extension, PDFs right in the app. Your data is stored in Canada and AI runs on my-id.ca's own servers, never sent to third-party AI providers.