Determine whether or not your friend or relative will need a letter of invitation. Letters of invitation are only required for residents of certain countries. Check with the Citizenship and Immigration Canada website for the most up-to-date list of foreign nationals requiring a letter. If your visitor's country of residence is on the website's list, then you will need to write a letter of invitation.
Obtain the following information from your visitor: complete name, date of birth, current address and telephone number, the purpose of her trip to Canada, how long she intends to stay in Canada, details about her accommodations and living expenses, and the date on which she intends to leave Canada
Write the letter of invitation. Be sure to write the letter in your own voice and include all of the information listed in the previous step. You will also need to include the following information about yourself: your relationship to the person visiting, your complete name, date of birth, address and telephone number in Canada, whether you are a Canadian citizen or permanent resident, and a photocopy of a document proving your status in Canada. Documents that can be used to prove your status are a Canadian birth certificate or a Canadian citizenship card. If you are a permanent resident of Canada but not a citizen, you must send a copy of your PR card or your IMM 1000 Proof of Landing document.
Have the written letter of invitation notarized by a notary public. Not all visa offices in Canada require notarization. Before getting your letter notarized, contact your local visa office for specific notary requirements.
Send your letter of invitation to the friend or relative you are inviting to visit Canada. He will need to submit your letter to a Canadian embassy or consulate outside of Canada for approval.