Can someone sign a contract on behalf of an Ontario corporation before it is incorporated?

Yes, but there are important liability implications. Under the Ontario Business Corporations Act, a person who enters into a contract in the name of or on behalf of a corporation before it is incorporated is personally liable on that contract. The corporation does not yet exist and therefore cannot be a party to a contract.

After incorporation, the corporation can adopt a pre-incorporation contract by express resolution of the directors or by acting on the contract in a way that demonstrates adoption. Once the corporation adopts the contract, the person who originally signed it is released from personal liability to the extent the adoption covers. However, if the corporation never adopts the contract, the original signatory remains personally liable.

This means that if you sign a lease, supplier agreement, or other contract before your corporation is incorporated, you should follow up with a board resolution adopting the contract as soon as possible after incorporation. If the other contracting party does not want personal liability to be released, they may insist on keeping the signatory personally bound regardless of adoption. This is a negotiable point. Getting incorporation done before signing significant contracts is the cleanest approach; if that is not possible, pre-incorporation contracts should be adopted promptly.