T4 slip boxes: what each number means and where it goes

What do the T4 slip boxes mean?

T4 slip boxes fall into three groups: income your employer paid you, amounts it withheld, and reference figures it used to do the payroll math. Only the first two groups end up on your return. The third group exists so you and the CRA can check whether too much CPP or EI was taken.

If you want the background on who issues the slip and when it arrives, start with our T4 slip explained page. This page is the box-by-box reference, including the numbers people most often enter in the wrong place.

Income boxes: T4 box 14 and line 10100

T4 box 14 is your total employment income for the calendar year before any deductions. It includes salary, wages, vacation pay, bonuses, commissions and taxable benefits. The amount goes on line 10100 of your return. If you had two jobs, add box 14 from each slip together and enter the total.

Box 42 shows commissions separately, but those commissions are already inside box 14. You enter box 42 on line 10120 only as an information line; it does not raise your income a second time.

Line 10100 vs 15000

Line 10100 holds employment income only. Line 15000 is total income: employment income plus everything else, such as EI from a T4E, interest from a T5, pension income and self-employment income. For someone with a single T4 and a small amount of bank interest, line 15000 will be slightly higher than line 10100. Our line 15000 total income page walks through the full list.

Deduction boxes: CPP, EI and income tax

Box 16 (or box 17 if you worked in Quebec) shows CPP or QPP contributions. Tax software splits the amount in two: the base part becomes a non-refundable credit on line 30800, and the enhanced part is deducted on line 22215. Box 16A holds the second additional contribution (CPP2), which is deducted on line 22215 as well.

Box 18 is your EI premium, claimed as a credit on line 31200. Box 22 is the income tax your employer sent to the CRA on your behalf; it goes on line 43700 and is subtracted from the tax you owe. A large box 22 relative to box 14 is the usual reason people get a refund.

Worked example: checking boxes 16 and 18 for 2026

Say box 14 shows $62,000 for 2026 and you had one employer all year. CPP is 5.95% of earnings between the $3,500 basic exemption and $74,600, so ($62,000 minus $3,500) times 5.95% is $3,480.75. EI is 1.63% of insurable earnings up to $68,900, so $62,000 times 1.63% is $1,010.60. If boxes 16 and 18 match those figures, the deductions are right.

What changes on 2027 T4 slips

The CRA has already posted the 2027 EI figures: maximum insurable earnings rise to $70,800 and the employee rate to 1.64% (1.29% in Quebec), for a maximum employee premium of $1,161.12 ($913.32 in Quebec). The 2027 CPP maximum pensionable earnings have not been announced yet; the CRA usually publishes them in November. Your 2026 T4, which employers must give you by the end of February 2027, still uses the 2026 figures above.

Taxable benefits and T4 slip box 40

T4 slip box 40 shows other taxable allowances and benefits, such as an employer-paid parking spot, a personal-use company car or a gift card. The amount is already included in box 14. Do not add box 40 to line 10100; doing so reports the same benefit twice and inflates your tax.

The "Other information" area at the bottom of the slip uses two-digit codes. Code 30 is board and lodging, code 34 is personal use of an employer's automobile, and codes such as 38, 39 and 41 relate to security options. Most codes are either already inside box 14 or need a separate line, and good tax software asks for each code by number.

Box 45 is a required code (1 to 5) describing whether your employer offered dental coverage. You do not enter it as income. It exists to help determine eligibility for the Canadian Dental Care Plan. The code reflects the coverage you could access on December 31, whether or not you used it:

• Code 1: not eligible to access any dental care insurance or coverage of dental services of any kind
• Code 2: payee only
• Code 3: payee, spouse and dependent children
• Code 4: payee and their spouse
• Code 5: payee and their dependent children

Pension and union dues boxes

Box 20 shows what you paid into a registered pension plan through payroll, deducted on line 20700. Box 52 is the pension adjustment: the value of the pension benefit you earned that year. It is not a deduction. It lowers the RRSP deduction limit printed on next year's notice of assessment, which is why workplace pension members see less room. Our RRSP contribution receipt page covers the other side of that calculation.

Box 44 shows union or professional dues taken from your pay, deducted on line 21200. If you paid dues directly to a union rather than through payroll, you claim those from the union's receipt instead.

T4 boxes that commonly confuse people

Why box 26 is different from box 14

Box 24 (EI insurable earnings) and box 26 (CPP or QPP pensionable earnings) are the figures your employer used to calculate premiums and contributions. They can be lower than box 14 because box 24 stops at the maximum insurable earnings ($68,900 in 2026) and because some taxable benefits are not insurable or pensionable. You do not enter them as income.

Other mix-ups worth checking

If a box is wrong, ask the employer for an amended T4 rather than typing a different number. If the slip never arrives, see what to do about a missing tax slip. For income that came on a T4A instead, such as commissions paid to a contractor, use the T4A slip guide.