Chapter 4 - Statutory and Non-Statutory Deductions
Summary :Three Categories of Payroll Deductions
Every amount withheld from an employee's gross pay falls into one of three groups, and a payroll clerk needs to know which group a deduction belongs to before deciding how it is calculated, remitted, and reported. The first group is statutory (source) deductions, which every employer in Canada is legally required to withhold regardless of what the employee wants: Canada Pension Plan contributions, Employment Insurance premiums, and federal and provincial income tax. The second group is other mandatory deductions, which are still compulsory but arise from a specific legal order or circumstance rather than applying automatically to every paycheque - a Requirement to Pay issued by the Canada Revenue Agency, a court-ordered wage garnishment, a family support order, or union dues owed under a collective agreement. The third group is non-mandatory (voluntary) deductions, which only come off pay because the employee has agreed to them in writing - health and dental premiums, life insurance, contributions to a registered pension plan above the mandatory minimum, or a payment redirected to a credit union. Getting this classification right matters because the legal remedy for an employer who withholds too little differs sharply between the three: shortfalls in statutory deductions expose the employer to CRA penalties and interest, while an unauthorized voluntary deduction can expose the employer to an employment standards complaint.
Canada Pension Plan Contributions
CPP is designed so that contributions are shared equally between employee and employer, and the calculation starts with a basic exemption of $3,500 per year, which is prorated across pay periods so that a small slice of each paycheque is contribution-free before CPP is applied to the remainder. Above the exemption, contributions apply up to the Year's Maximum Pensionable Earnings, which was $71,300 for 2025, at a combined base-plus-enhanced rate of 5.95 percent on the employee side for 2024 (employers match this dollar for dollar). Since 2024, a second tier - CPP2 - applies an additional 4 percent employee contribution on earnings between the YMPE and a second, higher ceiling, which was $81,200 for 2025. This second tier exists because the CPP enhancement was phased in specifically to lift the income replacement rate for higher earners, and it only touches the portion of an employee's annual earnings that falls in that upper band. Once an employee's cumulative contributions for the year reach the annual maximum, no further CPP should be withheld from that employer for the remainder of the year, which is why payroll software tracks year-to-date CPP contributions per employee rather than simply applying the rate to every cheque in isolation.
Calculating CPP - A Worked Example
Suppose an employee named Priya is paid bi-weekly (26 pay periods a year) with gross earnings of $2,400 for the period. The bi-weekly basic exemption is $3,500 divided by 26, which comes to $134.62. Subtracting that from gross pay leaves $2,265.38 of pensionable earnings for the period. Applying the 5.95 percent base-plus-enhanced rate gives an employee CPP contribution of $134.79 for that pay period, and the employer contributes the identical amount. If Priya's year-to-date pensionable earnings later cross the $71,300 YMPE threshold, any additional earnings up to $81,200 would instead attract the separate 4 percent CPP2 rate rather than the regular 5.95 percent rate, and once cumulative CPP2 contributions reach their own annual maximum, withholding would stop for that tier as well. This two-tier structure means a payroll clerk preparing a manual calculation late in the calendar year for a highly paid employee needs to check both YTD figures - regular CPP and CPP2 - before applying a rate, rather than assuming the same 5.95 percent applies to every dollar all year.
Employment Insurance Premiums
EI premiums are calculated only on the employee side up to an annual maximum insurable earnings ceiling, with the employer contributing 1.4 times whatever the employee pays - a ratio set in legislation to reflect that employers are the ones who lay off staff and therefore fund a larger share of the program. For 2024 the employee premium rate was 1.66 percent of insurable earnings, producing a maximum annual employee premium of $1,049.12, which rose to $1,077.48 for 2025 as the insurable earnings ceiling increased. Unlike CPP, EI has no basic exemption - the rate applies from the first dollar of insurable earnings. Using the same bi-weekly employee, Priya, with $2,400 of insurable earnings in a pay period, the EI premium is $2,400 multiplied by 1.66 percent, which comes to $39.84 for the period, and the employer's matching share is $39.84 multiplied by 1.4, or $55.78. As with CPP, once an employee's cumulative EI premiums for the calendar year reach the annual maximum, the employer stops withholding EI for the rest of the year, even if the employee changes jobs partway through and a new employer would otherwise start the calculation over.
Income Tax Withholding
Federal and provincial income tax withholding is the most complex of the three statutory deductions because, unlike CPP and EI, it is not a flat percentage - it depends on the employee's total annual income, the province of employment, the personal tax credits claimed on their TD1 forms, and any additional voluntary withholding the employee has requested. In practice, few payroll professionals calculate income tax by hand; the Canada Revenue Agency's Payroll Deductions Online Calculator (PDOC) is the standard tool, and it produces a defensible, auditable withholding figure once the employee's gross pay, pay period frequency, province, and TD1 claim amounts are entered. Because income tax brackets are progressive, the calculator effectively annualizes the pay period's earnings to estimate which bracket the employee falls into, then converts that back down to a per-period withholding amount, which is why doubling a bi-weekly pay period's gross pay does not simply double the tax withheld.
Other Mandatory Deductions
Beyond the three statutory deductions, an employer may be legally compelled to withhold further amounts. A Requirement to Pay is a formal notice from the CRA directing an employer to redirect an employee's wages toward that employee's outstanding tax debt; ignoring it makes the employer personally liable for the unpaid amount. Where an employer provides meals or lodging as part of employment, the value of that benefit is subject to prescribed deduction caps rather than being treated as fully taxable at cost. Court-ordered wage garnishments and family support orders are administered provincially and the rules differ meaningfully by jurisdiction: in Alberta, a garnishment order must leave the employee with at least $800 of net pay exempt from seizure, while family support enforcement bodies operate on separate ceilings - Ontario's Family Responsibility Office can direct up to 50 percent of an employee's net income toward support arrears, and Alberta's Maintenance Enforcement Program can direct up to 40 percent of gross income. An employer served with more than one garnishment or support order at once generally must satisfy support orders ahead of ordinary creditor garnishments, and payroll staff should never assume the caps are interchangeable across provinces.
Union Dues and Pension Plan Contributions
Where a workplace is unionized, dues are typically mandatory under what is known as the Rand Formula, a principle from Canadian labour law holding that because all employees in a bargaining unit benefit from a collective agreement, all employees - whether or not they choose to join the union - must contribute dues that fund the union's representation of the unit. This makes union dues a mandatory deduction even for a non-member employee covered by the agreement. Registered pension plan contributions can sit in either the mandatory or voluntary category depending on plan design: where an employer's defined benefit or defined contribution plan requires participation as a condition of employment, the minimum contribution is mandatory, while any additional voluntary contribution an employee elects to make on top of that minimum falls into the third category discussed below.
Non-Mandatory (Voluntary) Deductions
Voluntary deductions only leave an employee's pay because the employee has given written authorization, and an employer that deducts an amount in this category without that authorization risks an employment standards complaint. Common examples include premiums for employer-sponsored health and dental benefit plans, supplemental life or disability insurance, contributions to a workplace charitable giving program, and wage assignments - a standing instruction to redirect part of pay to a third party such as a credit union. Provincial rules cap how much of an employee's pay can be redirected this way: in Ontario, a wage assignment to a credit union is generally capped at 20 percent of wages, while British Columbia, Yukon, and Alberta apply their own variations on the permissible cap and process. Because these deductions are optional, an employee can generally revoke the authorization going forward, and the employer must stop the deduction from the next practical pay period once notified, unlike statutory or court-ordered deductions, which continue regardless of the employee's wishes.
Quick Revision Summary
Payroll deductions split into three categories: statutory (CPP, EI, income tax - compulsory for every employee), other mandatory (RTP, garnishments, support orders, union dues - compulsory once triggered by a legal order or agreement), and non-mandatory (health plans, extra insurance, wage assignments - only with the employee's written consent). CPP for 2025 applies at 5.95 percent above a $3,500 basic exemption up to the $71,300 YMPE, with a further 4 percent CPP2 tier up to $81,200. EI for 2024 applied at 1.66 percent from the first dollar up to a $1,049.12 annual maximum, rising to $1,077.48 for 2025, with employers matching at 1.4 times the employee premium. Income tax withholding is calculated through the CRA's PDOC tool rather than a flat rate. Garnishment and support-order limits vary by province - Alberta preserves an $800 exemption on garnishments, Ontario's FRO can reach 50 percent of net income, and Alberta's MEP can reach 40 percent of gross income - so payroll staff must apply the rule of the province where the employee is paid, not a single national figure.