What happens if you requested an extension for last years taxes but the forgot to file? Will there be penalties?

[rjs]

Your extension from last year has expired. You are now just filing late. If you are getting a refund there is no penalty for filing late. If you owe tax, you will have to pay penalties and interest. The sooner you file and pay, the less the penalties and interest will be.

[macuser_22]

If you owed additional tax then that tax was due on the due date for that years tax return extension or not 0 the extension is only an extension to *file*, not to pay so penalties and interest started on the due date of the tax return.  If you owed tax and *did* pay then there could be an additional failure to file penalty.

If you were due a refund then  the only penalty is that the government has your money and not you.