A tax refund happens when a taxpayer has paid more taxes throughout the year than they actually owe in taxes. 

When is a tax refund issued?

published by:thehyperbusiness.com

If you have tax liability of $5000 but have paid $6000 through payroll withholding, you would receive tax $1000 refund. 

For insance,

This can occur for a variety of reasons, including:

Over-withholding : If an employee has too much tax withheld from their paycheck

Tax deductions and credits : If the amount of deductions and credits exceeds the amount of tax owed

Estimated tax payments: If the estimated payments exceed the actual tax liability

Amended returns: If the amended return results in a lower tax liability, the taxpayer may be eligible for a refund.

But remember: Refunds are not automatically issued by the IRS. Taxpayers must file a tax return in order to receive a refund.

24 hours after e-filing a previous year tax return

Normally it takes:

3 or 4 days after e-filing for prior to the previous year

4 weeks or more after filing a paper return

You can track your refund status here-

You can Call IRS about your refund status if where's My Refund directs you to contact.