what type of LLC? A single member LLC does not file a separate federal return. Rather the income and deductions are included in your 1040. Every domestic partnership must file Form 1065, unless it neither receives income nor incurs any expenditures treated as deductions or credits for federal income tax purposes.
Entities formed as LLCs that are classified as partnerships for federal income tax purposes have the same filing requirements as domestic partnerships.
the penalty for late or non-filing the 1065 is around $200/partner/month for up to 12 months.