Certain criminal records may exclude you from travel into some countries. A Waiver is a document, issued by the country to which you would like to travel, allowing you to enter even if you do not meet the entry requirements. For example, the United States restricts entry for people who have been convicted of certain crimes. You can find a list of what these crimes are at www.state.gov
If you have a record of one of these crimes, you will need a Waiver of Inadmissibility to enter the US. Never try to travel to the US if you are excluded: you could be detained, fined, charged or incarcerated.
The waiver is issued by US Customs & Border Protection (CBP), an agency of the Department of Homeland Security, and carries a short term. You can apply by filling out Form I-192 and submitting the required documents. The list of crimes, Application Form and instructions can be found on the US Citizenship & Immigration website: www.uscis.gov and the application is submitted at a CBP Port of Entry.
The application process can take up to a year and is expensive. The costs will depend on the types of documents you need to submit, but the application itself costs $585.00 US (as of 2012).
If you have obtained a record suspension, you may still need a waiver to travel to the US. Border officials may have access to different kinds of information than Canadian police and do not recognize a Canadian Record Suspension. Even a conditional discharge for certain offences can exclude you from entry.
For more information, read the CBP website: www.state.gov, contact your nearest Port of Entry, or call the Pearson Airport CBP Centre: 905- 676-2606.