When processing applicants who request temporary entry in accordance with the post-sale provision of Appendix 1603.A.1, copies of the original contract for sale, warranty or service and renewals of such agreements are required. In the 1980s, the governments of Canada, Mexico and the United States negotiated a regional free trade agreement known as NAFTA.  The heads of state and government of the three nations signed the agreement on 17 December 1992 in their respective capitals.  This does not mean that a warranty or service contract must have the same date as the sales contract. For services provided by third parties in particular, it may take a few months after the sale before the company that installed or maintained the machine is identified and contracted. The text of the actual agreement appears in Part V, Chapter 16. The initial guarantee or service contract may be renewed, provided that the sale contract or the original warranty or service contract includes a provision for renewal. The after-sales service therefore continues to be contractually bound in connection with the sale of equipment or machinery or computer software. While NAFTA provides only for after-sales situations, the general R187 rule for business travellers, under which this section of NAFTA is implemented, allows individuals to participate in sales and leasing contracts. The documentation requirement was imposed to make it clear that the proposed activity is incidental or related to the sale of devices or machinery or computer software. The other parties to the agreement meet the same requirements.
Canadian employees of TN are responsible for U.S. Medicare, State, Federal and Social Security Taxes in the United States. U.S. NT employees in Canada are also subject to corresponding income taxes and tax filing at the end of the year in Canada. As a general rule, income tax is mandatory depending on where the worker works, regardless of where a legal or physical stay is maintained during employment. It is a bit like American citizens who live in one state but work in another state, who are then subject to public income and other taxes in the state where they work. If their legal residence is still in their country of origin, workers may also be required to return to their country of origin. On the basis of income tax agreements, a credit for income and other taxes on wages paid abroad is generally available in the country of origin.