Useful links:

Register an account with CRA

Make a payment to CRA

Child and family benefits

Payroll deductions online calculator

Important CRA phone numbers:

Individual Income Tax Inquiries 1-800-959-8281

Business Tax Inquiries 1-800-959-5525

Canada Child Benefits 1-800-387-1193

GST Credits 1-800-959-1953

Canada Pension Plan (CPP) and Old Age Security (OAS)

Employment Insurance 1-800-206-7218

Forms and Publications 1-800-959-2221