C.R.S. § 44-30-602

Not later than fifteen days following the end of each retail month, each licensed retailer shall make a return and remittance to the director on forms prescribed and furnished by the director. The director may grant an extension of not more than five days for filing a return and remittance; except that the director shall not grant more than two extensions during any one-year period. Unless an extension is granted, a penalty or interest under section 44-30-604 shall be paid if a return or remittance is not made on time.