How do you spell carry over when it modifies a noun?

The term 'carry over' is both a noun and a verb. The noun form is a closed compound noun, which can modify another noun, a function called an attributive noun. Example:

The carryover is put aside for the next project.

The carryover funds are put aside for the next project.

The verb function is a verb, adverb combination, which is written as two separate Words. Example:

We carry over the funds for the next project.