What evidence should I gather before starting a lawsuit in Ontario?

Gathering strong evidence before filing a claim in Ontario dramatically improves your position. Courts decide disputes based on evidence, and the better organized and documented your case, the stronger your position in settlement discussions and at trial.

Start by collecting all written communications related to the dispute: contracts, invoices, emails, text messages, letters, and notes from phone calls or meetings. Document dates carefully — when the agreement was made, when problems arose, when you raised concerns, and when the other party responded. Photographs, videos, receipts, bank records, and inspection reports can all be critical depending on the type of claim.

Identify potential witnesses — people who saw or heard relevant events or who have specialized knowledge. Make notes of what each witness knows while memories are fresh. If possible, get written statements from witnesses.

Organize your evidence chronologically and by category so you can present your case clearly. Keep originals of all documents and make copies. Courts look at consistency and credibility, so avoid altering records or filling gaps with guesswork.

A lawyer can review your evidence before you file, identify weaknesses, advise on what additional evidence to seek, and assess whether your case is strong enough to justify the cost of litigation.