The governing documents have an order of authority, and it decides arguments. State common-interest-community law sits at the top and cannot be overridden by an association. Below that is the recorded declaration, which creates the community, defines the units and the common elements, and states the substantive restrictions. Below that are the bylaws, which govern how the association operates: the board, elections, meetings, quorum, voting. At the bottom are the rules and regulations the board adopts within its delegated authority. A board rule inconsistent with the declaration or with a statutory right is generally unenforceable, which is why an owner in a dispute reads from the top of the stack rather than from the letter they received.
Assessments are the association's income and they are secured. Regular assessments fund the operating budget and the reserves; a special assessment is levied when a cost exceeds what has been reserved. In a common-interest community the obligation to pay is generally secured by a statutory lien on the unit, which arises automatically rather than by agreement. The Uniform Common Interest Ownership Act, a model act that many states have adapted, provides at section 3-116(k) that the lien may be foreclosed "in like manner as a mortgage on real estate," and at section 3-116(p) limits foreclosure where the sums due consist of fines alone. States that have not adopted the model act reach the question their own way, so whether and how quickly an association can foreclose is a state-by-state answer rather than a general one.
Whether anything caps an assessment is a question with a different answer in different states. Some states constrain a board directly: California, for example, bars a board from imposing assessments that aggregate more than 5 percent of budgeted gross expenses without member approval, while carving out emergencies from that limit. Others leave the ceiling, if any, to the declaration. So neither of the two things owners commonly assume is safe to assume: not that assessments are simply uncapped, and not that a required owner vote is a reliable ceiling. The question has to be answered from the state's statute and the declaration together. What is available everywhere is the paperwork: the budget, the reserve study and the recent minutes, which together show whether the association is funding what it will eventually have to replace.
Enforcement runs in several directions and not all of them involve money. Depending on the documents and the state, an association may levy fines, suspend the use of common amenities, suspend voting rights, obtain an injunction, record a lien, and in some cases foreclose. It may also be constrained: many states require notice and an opportunity to be heard before a fine, and federal fair housing law limits how rules may be applied and requires reasonable accommodations in some circumstances.
The federal tax definition is narrow and does a different job. Section 528 of the Internal Revenue Code defines a homeowners association as a condominium management association, a residential real estate management association or a timeshare association that is organized and operated to acquire, construct, manage, maintain and care for association property, and that meets two proportion tests: at least 60 percent of gross income must consist solely of membership dues, fees or assessments from owners, and at least 90 percent of expenditures must go to association property. An association meeting those tests may elect to file Form 1120-H, under which its assessment income is exempt function income that is not taxed, and only its other income, typically interest on reserves, is taxed. The rate is a flat 30 percent, or 32 percent for a timeshare association, after a $100 specific deduction. That definition governs a tax filing choice and nothing else: what an association may do to an owner is a matter of state law and the recorded documents.