How does a condo association report owners delinquent in paying their condo fees?

Most associations have a collection policy. The policy should be drafted by an attorney who specializes in condominium law.

Generally, a delinquent owner is first notified by a demand letter explaining how much is owed and that legal action will be taken if the delinquent fees are not paid immediately. If that doesn’t work the association can file a lawsuit in the proper court depending on jurisdictional limits. If the association prevails it can obtain a judgment lien to file against the unit.

The final option if all else fails is to foreclose on the lien in court. The association should consult with its attorney if that step becomes necessary.
The association wants to do more than report owners delinquent. The association wants to collect the debt.

Check your governing documents to discover whether or not your assessments are automatically liens against the units. If so, then the association's attorney can file a formal lien.

The board may also have additional recourse to collect unpaid assessments, including perhaps selling the unit in order to satisfy the debt.

One way is to report the delinquent unit owners to a collections company, though these companies usually charge outrageous fees. I suggest the association retain a real estate attorney and file liens against the delinquent units. These liens may be foreclosed if not paid, which will be an incentive for the delinquent unit owners to pay up. Don't try to file liens without an attorney--if done incorrectly, thousands of dollars in attorney fees will likely be spent. The liens will then show up on the delinquent owners' credit reports.

In most states, it is not legal to publish a debtor's name, but you may be able to publish the unit number in your financial reports and board meeting minutes.
Once a lien is filed, it becomes public record and can appear on an owner's credit report.