Section 55. Alternative sentence of imprisonment

When a fine is imposed, an alternative sentence of imprisonment from one to 120 days is set. The alternative penalty may be executed when the conditions of section 456, second paragraph, first sentence of the Criminal Procedure Act have been fulfilled.
An alternative sentence of imprisonment lapses upon full payment of the fine. If part of the fine is paid, the sentence of imprisonment is proportionally reduced, calculated in whole days.
If a fine has been imposed on an enterprise pursuant to section 27 or an offender who was under 18 years of age at the time of the act, a sentence of imprisonment pursuant to the first paragraph shall not be set.