Border officers in Canada no longer use personal judgment when deciding who to let across the border. There are strict guidelines and restrictions that they follow. Regardless of how long you plan to spend in Canada or why you're visiting, a criminal record could prevent you from entering the country. Crimes, such as driving under the influence or even writing a bad check, can give a border officer grounds to not permit you admittance to the country, even if the offence happened many years ago. For this reason, if you have a criminal record, entering Canada will be a bit tricky and require more preparation than for the average person.
Gather the necessary documents to carry into Canada if you have been deemed rehabilitated. These documents usually include your conviction statement, proof that you have completed the sentence and that you have not had any criminal offences in the past five years (or 10 years if you were indicted).
Apply for a rehabilitation declaration with the Canadian consulate to get your criminal record deleted from the database used by Canadian border officers. This process can take up to a year or sometimes longer. When applying, you need to prove hat you completed your sentence at least five years ago and that you have not had any other criminal convictions since then.
Apply for a temporary residence permit (TRP) to enter Canada, if not enough time has passed since your crime. This is done through a Canadian border officer at the nearest consulate. Have documentation of your conviction, proof that you finished your sentence and haven't received any new convictions. The officer will examine your documents, interview you, and decide on a subjective basis whether or not you should be granted a TRP. Depending on your specific situation and the determination of the officer, your TRP will be good for as little as a few days or up to a full year.
Avoid lying or misrepresenting yourself when being questioned by Canadian border officers or authorities. Doing so could result in a fine of up to £65,000, imprisonment of up to five years, and banishment from entering Canada for up to two years.