Take the time to brush up on the law in your city and state regarding annual reporting of tax-exempt status. One eastern city requires tax-exempt organizations to file each year for continuation of that status. Because the city did not enforce that requirement until 2007 (when a new assessor took office), one UU congregation received tax bills for two consecutive years before it recognized it had a requirement to file an annual statement.
The city sold the unpaid tax bills (with interest they total more than $200,000) to a collection agency and the congregation had to hire a lawyer to sort everything out. Many months later negotiations are continuing with the city. Because the tax leins went to collections, the issue is more complicated to resolve. The congregation does not know what its ultimate liability might be.