Deficiency deduction for associations allows member receipt shortfalls to be claimed, subject to carry forward rules and a capped limit. Associations may deduct the shortfall between member receipts (excluding remuneration for specific services) and qualifying non-capital expenditures for members' common interests as a deficiency, first applied against business/professional income and then against other heads if necessary; carry forward and set off provisions must be given effect first, and the deduction is capped at one-half of the total income. The section applies only where income is not distributed to members except as grants to affiliated bodies, and excludes amounts deductible under other provisions or capital expenditures.