A company key in Ontario is a nine digit code that unlocks your business profile in the Ontario Business Registry. You need it to file or change anything about your business online, and since February 1, 2025 every entity in the registry must use one to transact, whether you file yourself or have a lawyer do it for you.
If your business was incorporated or registered on or after October 19, 2021, you already received a key. If it predates that, you almost certainly do not have one yet, and you need to request it before your next filing. This guide explains what the key is, how to get it, how your lawyer uses it on your behalf, and the mistakes we watch clients make so you can avoid them.
What is a company key, and what does it actually do?
The company key is a confidential passcode the Ontario government issues for each registered business. The registry treats it like a banking PIN. Anyone who holds it can view and change your business record, so the key controls who is allowed to act for your company on the public file.
The Ontario Business Registry is the province’s online system for corporations, not for profit corporations, and registered business names. It launched on October 19, 2021 and now handles over 90 different transactions, from incorporating a company to filing an annual return to dissolving a business. The company key is the credential that lets you reach into your own record and make those filings.
People often mix the company key up with two other numbers. Your Ontario Corporation Number and your Business Identification Number both appear on your public record and help others find your business. The company key does the opposite. It stays private, and it is the only one of the three that grants the power to make changes. Keep all three, but guard the key.
Table 1. The company key compared with your other business identifiers
| Identifier | What it is | Public or private | What it lets you do |
|---|---|---|---|
| Company key | A nine digit code unique to your business | Private, keep confidential | Access and change your business record in the registry |
| Ontario Corporation Number | The number assigned when you incorporate | Public | Identifies your corporation on the registry |
| Business Identification Number | A nine digit number tied to a registered business name | Public | Identifies your registration to banks, suppliers, and the province |
| Ontario.ca Login | Your personal sign in for government services | Private | Signs you in so you can open your Ontario Business Account |
Do you need a company key? What changed on February 1, 2025
Yes, if you want to file anything in the registry. Before February 2025, many older businesses could still file through an intermediary without ever touching a key. That route closed. Effective February 1, 2025, the Ministry requires a company key for every transaction in the registry, whether you file directly online, through a lawyer or accountant acting as your intermediary, or through a licensed service provider.
New businesses get the key automatically. When you register a business name or incorporate through the registry, the Ministry sends the key to your official email on file. Businesses created on or after October 19, 2021 should already have received it.
Older businesses do not have one. If your corporation or registration predates October 19, 2021, the province migrated your record into the new registry but never assigned a key. You have to request it. In our practice this is the single most common surprise for established companies. The owner assumes the business has always had a key because it has operated for years, then learns it needs one the week an annual return is due.
How do you get your company key in Ontario?
You request it from the Ministry for free. The company key itself costs nothing. You only pay if you ask a third party to retrieve it for you, and that is a convenience fee for their time, not a government charge. You request the key in four steps.
- Go to the Ontario Business Registry and open the Get your company key tool.
- Search for your business using its registered name, Ontario Corporation Number, or Business Identification Number.
- Confirm that the business details the registry shows match your records.
- Choose how you want to receive the key.
If your business has a current official email on file, the registry emails the key right away. If there is no email on file, the Ministry mails it to your registered office or principal place of business, which can take several days. If your address recently changed, you may be able to answer a few verification questions and have the key emailed to you immediately through the online tool. The official company key guide walks through each screen.
The lesson here is simple. Keep your official email current in the registry. The province sends your key, your annual return reminders, and other important notices to that address. If it points to a former bookkeeper or an inbox no one checks, you lose the fastest route to your own key. The law already requires you to update your registry information within 15 days of any change, so make the email a priority.
How your lawyer uses your company key (Delegated Authority)
You do not have to file anything yourself. Most of our business clients prefer to hand the filing to us, and the registry is built for that. A law firm, accountant, or other agent counts as an intermediary, which means we have authority to act on your behalf in the registry. If you would rather have help, you can speak with a small business lawyer before anything is filed.
Here is the part many articles get wrong. Using an intermediary does not remove the company key requirement. We still need your key to act for you. The difference is that you provide it once. When you give us the key, we claim Delegated Authority over your record in the registry system. That authority stays in place for future filings until you revoke it, so you are not digging out the key every year.
In our practice the work usually runs in a clear order. You book a short consultation. We confirm the registry holds the correct legal name, directors, and address for your business. We then request or collect the company key. Once we hold Delegated Authority, we handle the filing you came in for and the routine filings after it, such as your annual return or a notice of change when a director leaves. You keep a record of the key in case you ever want to file on your own or move to a different representative.
Should you file yourself or use an intermediary?
Both routes are legitimate. The right one depends on how often you file, how complex the filing is, and how comfortable you are inside the registry. A sole proprietor renewing a business name can often do it alone in twenty minutes. A corporation amending its articles or cleaning up years of missed annual returns usually wants help.
Table 2. Filing your own registry transactions compared with using an intermediary
| Consideration | File it yourself | Use a lawyer or intermediary |
|---|---|---|
| The company key | You request and manage it | You provide it once, we hold Delegated Authority |
| Best suited for | Simple, routine filings like a business name renewal | Incorporations, amendments, share changes, backlogged returns |
| Cost | Free key plus the government filing fee | Government fee plus a professional fee for the work |
| Sign in setup | You create an Ontario.ca Login and Ontario Business Account | We file through our registry access, no account setup for you |
| Who carries error risk | You do | We review the filing before it goes in |
| Ongoing filings | You repeat the steps each time | We can handle them as they come due |
If your filing is routine and you have your key and login ready, do it yourself. If the filing affects your share structure, your directors, your corporate name, or your good standing, the cost of getting it wrong is higher than the cost of having it done properly. That is the line we draw with clients.
What you can do in the registry once your business is linked
After you link your business with your company key, your record sits inside your Ontario Business Account and you can transact directly. Common filings include renewing a business name registration, filing your corporation’s annual return, filing a notice of change when directors or addresses change, amending your articles, and dissolving a business you no longer need. Keeping these filings current is also part of maintaining a clean corporate minute book.
Company key mistakes we see, and what they cost
None of the problems below are hard to avoid. They cost time and stress mostly when a filing deadline is already close.
- Letting the official email go stale. The key and your annual return reminders go to an address you abandoned. You then wait days for a mailed key or work through verification. Update the email first.
- Requesting the key the week a deadline lands. A mailed key can take several days. If your annual return or a name renewal is near, request the key early so a slow delivery does not push you past the date.
- Treating the key like a public number. The key is not your corporation number or your Business Identification Number. Anyone who has it can change your record. Share it only with a representative you trust, and only once.
- Assuming an old business already has a key. Companies formed before October 19, 2021 were never assigned one. Check before you need it.
- Forgetting to revoke Delegated Authority. If you change accountants or law firms, the former representative keeps access until you revoke it. Close that door when the relationship ends.
A few minutes of housekeeping now, confirming your email, locating your key, and knowing who holds Delegated Authority, removes the scramble later.
Frequently asked questions
Is the company key the same as my BIN or corporation number?
No. Your Business Identification Number and your Ontario Corporation Number identify your business on the public record, and other people can see them. The company key is private and is the only one that lets someone change your registry record. Keep all three, but never treat the key as a public number.
How long does it take to get a company key?
If your business has a current official email on file with the registry, the key arrives by email right away. If there is no email on file, the Ministry mails it to your registered or head office address, which can take several days. If your address recently changed, you may be able to answer verification questions and receive it by email immediately.
Do I still need a company key if my lawyer files everything for me?
Yes. Since February 1, 2025 every registry transaction needs a key, including filings made by an intermediary. The useful part is that you provide it only once. After you give your lawyer the key, the firm claims Delegated Authority and can file for you going forward until you revoke that authority.
I cannot find my company key. What do I do?
Request it again. The key is a one time code tied to your business, and you can retrieve it through the registry’s Get your company key tool using your registered name, corporation number, or Business Identification Number. If the online tool cannot verify you, call the ServiceOntario Contact Centre for help.
Is there a fee for a company key?
No. The Ministry issues the company key for free. You only pay if you hire a service provider or law firm to retrieve it or to handle your filings, and that fee covers the work, not the key itself.
My corporation was set up before October 19, 2021. Do I have a key?
Almost certainly not. The province moved older records into the new registry but did not assign company keys to businesses that predate the launch. You need to request one before you can file. It is worth doing this now rather than the week a return is due.
The information provided above is of a general nature and should not be considered legal advice. Every transaction or circumstance is unique, and obtaining specific legal advice is necessary to address your particular requirements. Therefore, if you have any legal questions, it is recommended that you consult with a lawyer.
