Invoice Void & Allowance (作廢 / 折讓)

STATUS: SKELETON — body pending.

When to use this skill

• A return / refund occurs within same bimonthly → void
• A return / refund crosses bimonthly boundary → 折讓
• Debugging invoice state inconsistency post-refund
• Building void / allowance SOP

Do NOT use when

• Initial issuance → issuance-layer skill
• Tax filing impact → tw-tax-basics

Core concepts