If you’re required to lodge a tax return by a certain date and you don’t lodge it, you may receive a failure to lodge (FTL) on time penalty. The ATO will get in touch with you via SMS, MyGov message, phone or letter before giving any penalties. Penalties are calculated one penalty unit for every 28 days your tax return is due with each penalty unit for small businesses being $222 and can go up to a maximum of $1,110. For medium and large businesses this penalty will be much larger.