There is a difference between uncollected dues and/or assessments and uncollectible ones. Uncollected dues remain on the balance sheet as accounts receivable. Uncollectible dues (no longer covered by lien) must be written off accounts receivable as Bad Debt Expense. In my view, the budget should include the best estimate of the Bad Debt Expense, even though the intent is to collect all dues and assessments.
Part of the difficulty in handling uncollected and uncollectible dues and assessments is the tendency to book dues income as the total amount billed, rather than the total amount actually collected. See discussion concerning
Accounting for Deferred Revenue for some ideas. Other comments are welcome.
Unfortunately the questions of how to handle uncollected and uncollectible dues is that the applicable accounting standard, the AICPA Audit & Accounting Guide for Common Interest Realty Associations, does not provide guidance.