Canadian tax slips
T4 and Relevé 1 slips, read box by box.
Drop your clients' slips, one by one or in a ZIP, and get every box as structured data. Social insurance numbers are masked, slips are grouped by tax year, and uncertain values wait for your review.
T4 slips are included from the Pro plan, RL-1 slips from the Ultra plan. Start on the free plan to try invoices first.
Tax season means hundreds of slips typed by hand
Each client brings T4 and RL-1 slips as PDFs, photos or paper scans.
Every box must be retyped into the tax software, often twice for Quebec residents.
A missing slip or a duplicate is easy to miss when the deadline is close.
How it works
Upload
Drop slips one by one, or a ZIP with every client document: each slip is detected separately.
Extract
Every box is read; the social insurance number is masked to its last digit.
Cross-check
The tax folder groups slips by year and employer, flags missing slips and duplicates, and compares year-to-date payslip amounts with the boxes.
Export
Export to CSV or JSON, or send the data to your tools through the API and webhooks.
What is extracted
Boxes that are empty on the slip come back empty, never estimated.
T4 (CRA)
- Tax year, province, employment code
- Employer name, address and payroll account number
- Employee name; SIN masked
- Boxes 14, 16, 17, 18, 20, 22, 24, 26, 44, 46, 52, 56 and any other box present
RL-1 (Revenu Québec)
- Tax year and slip code
- Employer name, address and NEQ
- Employee name; SIN masked
- Boxes A to W, including QPP, QPIP and Quebec income tax withheld
A T4 slip as structured data
Fictitious T4 for a Quebec employee (boxes trimmed for reading).
{
"documentType": "T4",
"extractedData": {
"taxYear": 2025,
"employerName": "Example Manufacturing Inc.",
"employeeName": "Alex Sample",
"socialInsuranceNumber": "***-***-**7",
"province": "QC",
"boxes": {
"box14": 58250,
"box17": 3786.25,
"box18": 762.08,
"box22": 7340.5,
"box24": 58250,
"box26": 58250,
"box56": 287.75
}
},
"reviewRequired": false
}Formats and limits
What you can send
- PDF, PNG, JPG and WEBP slips
- ZIP files with many slips (batches)
- Up to 10 MB per file
What you get back
- JSON per slip, in the app or through the API
- CSV and JSON export of the yearly tax folder
- Signed webhooks for your own workflow
Good to know
- DocuSense extracts the data; it does not file returns or give tax advice.
- Handwritten or heavily damaged slips may need a manual check.
Sensitive data, handled carefully
- Social insurance numbers are masked to their last digit, in the model instructions and again in code.
- Original files are deleted once processed; only the extracted data is kept, and you can delete it at any time.
- Two-step sign-in and a full activity log on every account.
Frequently asked questions
Which plan do I need for T4 and RL-1?
T4 slips are included from the Pro plan and RL-1 slips from the Ultra plan. The free plan lets you try DocuSense on invoices first.
Is the social insurance number stored?
No. It is masked to its last digit (***-***-**7) before the result is saved.
Can I upload all of a client's documents at once?
Yes. Upload a ZIP: each slip is detected, classified and extracted separately, within your plan's limits.
Does it compare slips with payslips?
Yes. The tax folder compares the year-to-date amounts of the last payslip with the slips of the same employer and flags differences.
Does DocuSense file the tax return?
No. DocuSense extracts and checks the data; you import it into your tax software or your own workflow.
Be ready before the slips arrive.
Set up your account now, try it on invoices for free, and upgrade when tax season starts.