A T4 slip is the basic document that an employer must prepare to account for any remuneration that it pays to an employee. The employee uses it to prepare income tax returns, and it is the Canada Revenue Agency’s first tool to ensure compliance by salaried workers. As an employer, you must prepare T4 slips for all individuals who received more than $500 in remuneration from you, or if you deducted CPP/QPP contributions, EI premiums, PPIP premiums, or income tax for that employee. Remuneration includes salary, wages, tips, bonuses, vacation pay, employment commissions, and all other types of remuneration you may have paid to an employee during the year. It also includes any taxable benefits and retirement allowances.