Tax owing after proper withholdings

[BlueMatia]

If a person only has employment income (T4/RL1) from one employer on their tax return and no other income or expenses, does it make sense that they would have a large tax owing at the end of the year? Shouldn't the employer have withheld the proper amount throughout the year resulting in little to no tax due at the end of the year? (Taxpayer claiming only basic amount on TD1)

[TurboTaxGinette]

Unfortunately, it is up to the employee to request an increase in taxes taken from their income on their TD1. 

Thank you for choosing TurboTax.

[BlueMatia]

If an employee has a salary of $100k annually...shouldn't the withholdings per pay be based on that annual salary? 

Why would the employee need to request an increase in taxes if they didn't have a second job?  and how would the employee know to ask , doesn't make sense 

[TurboTaxGinette]

To discuss this and clarify these rules, you will need to call the Canada Revenue Agency (CRA) at 

1-800-959-8281.

Thank you for choosing TurboTax.