Understanding Your T4 Slip: A Guide for First-Time Filers

Every February or March, your employer sends you a small piece of paper - or a PDF in your HR portal - that feels like it was designed to be confusing. If you’ve never filed taxes before, staring at a T4 slip full of numbered boxes and dollar amounts is genuinely disorienting. Nobody explains what Box 14 means versus Box 22, or why some numbers are bigger than what you expected, or what you’re actually supposed to do with any of it. The good news is that a T4 is simpler than it looks. Once you know what each section is doing, you’ll be able to pick up any T4, understand it in under two minutes, and use it confidently when you file. This guide walks through the whole thing - including what to do if your numbers seem wrong and the difference between a T4 and a T4A.

What a T4 Slip Is and Why You Get One

A T4 - formally called a Statement of Remuneration Paid - is the document your employer sends to both you and the CRA every year. It summarizes everything your employer paid you and deducted from your paycheques during the calendar year. The CRA uses your employer’s copy to cross-check your tax return, which is why it’s important that your numbers match exactly.

You should receive a T4 from every employer you worked for during the tax year. If you held two jobs - say, a retail shift and a campus job - you’ll have two T4s. Both need to be included when you file.

If you worked as an employee, you get a T4. If you did contract or freelance work, you typically get a T4A instead (more on that below). If you worked for a staffing agency, the T4 comes from the agency, not the business you were placed at.

The Boxes That Matter Most

The T4 has around 30 numbered boxes, but most people only need to focus on a handful.

Box 14 - Employment Income. This is the big one. It shows your total employment income for the year before any deductions. This number goes directly into Line 10100 on your tax return. If you earned $38,000 working at a company from January to December, Box 14 will show $38,000.

Box 22 - Income Tax Deducted. This is how much federal and provincial income tax your employer withheld from your paycheques across the year. This is the number that determines whether you get a refund or owe more. If CRA’s calculation of what you owe is less than what’s in Box 22, you get the difference back.

Box 16 - CPP Contributions. The Canada Pension Plan deductions taken from your pay throughout the year. If you’re under 18 or over 70, this box may be empty.

Box 18 - EI Premiums. Employment Insurance deductions. Most employees pay into EI. The amount in Box 18 becomes a credit on your return that reduces your taxes slightly.

Box 52 - Pension Adjustment. If you’re in a workplace defined benefit pension, this box tells the CRA how much RRSP contribution room to reduce. For most students and young workers, this box is blank.

Quick tip: When you open your tax software - whether that’s Wealthsimple Tax (formerly SimpleTax), TurboTax, or another CRA-certified tool - it will ask for your T4 boxes one at a time. You don’t need to memorize any of this. Just have your T4 open beside you and fill in what’s asked.

How to Use Your T4 to File

Once you have your T4 in hand, filing is mostly a matter of entering the numbers into CRA-certified tax software and letting it do the math.

The most popular free option for Canadians is Wealthsimple Tax. It’s genuinely free for simple returns - no upsell for T4 income, students, or basic investment income. You create an account, enter your T4 box numbers when prompted, add any other slips you have (T2202 for tuition, T5 for interest income), and the software calculates whether you’re getting a refund or owe money.

Once you submit, you’re filing via NETFILE - the CRA’s secure electronic submission system. Most returns processed through NETFILE get any refund deposited within 2 weeks if you’re signed up for direct deposit with the CRA.

Keep your T4 for at least six years. The CRA can audit past returns and you’ll need your slips as documentation.

T4 vs T4A: What’s the Difference?

A T4 is for employment income - money earned as an employee where your employer withheld taxes, CPP, and EI automatically.

A T4A is for other types of income: freelance or contract work, scholarships, bursaries, grants, and some pension income. If you did a paid co-op placement through your school, received a scholarship of more than $500, or did contract work for a business that paid you directly, you may get a T4A.

The key difference: T4A income often has no tax withheld at source, which means you may owe money when you file rather than getting a refund. This surprises a lot of first-time freelancers and scholarship recipients. If you receive a T4A, set aside roughly 20–25% of that income for tax time.

Frequently Asked Questions

What if I didn’t receive my T4?

Your employer is required to issue your T4 by the last day of February. If you haven’t received it by early March, check your online HR portal or employee self-service system first - most large employers post them there. If you genuinely can’t get it, contact your employer’s payroll department. As a last resort, the CRA may have a copy through the Auto-fill my return feature in certified tax software.

What is Box 14 on a T4?

Box 14 is your total employment income - the gross amount your employer paid you during the tax year before any deductions were taken. This is the number you report as employment income on your tax return (Line 10100). It includes regular wages, overtime, bonuses, and taxable benefits your employer provided.

Can I file my taxes without my T4?

Technically you can estimate, but the CRA will compare your return to the T4 your employer filed on their end. If the numbers don’t match, your return may be flagged or reassessed. It’s worth waiting for your T4 before filing. If your employer is late, contact them directly or call CRA at 1-800-959-8281.

What if the income in Box 14 seems wrong?

Add up your paycheque stubs from the year and compare the total gross income to Box 14. Small discrepancies can happen due to taxable benefits (like a gift card or group insurance premium your employer paid on your behalf). If there’s a significant difference, contact your employer’s payroll department - they’re required to issue a corrected T4 (called a T4 Amendment) if an error occurred.

Do I need to attach my T4 to my tax return?

If you file electronically through NETFILE - which is how most Canadians file - you don’t attach any slips. You just enter the numbers. Keep the original T4 in your records for at least six years in case the CRA asks for documentation during an audit or review.

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