Explanation
This inefficiency occurs when Savings Plans are purchased within the final days of a calendar month, reducing or eliminating the ability to reverse the purchase if errors are discovered. Because the refund window is constrained to both a 7-day period and the same month, late-month purchases materially limit correction options. This increases the risk of locking in misaligned commitments (e.g., incorrect scope, amount, or term), which can lead to sustained underutilization and unnecessary long-term spend.
Relevant Billing Model
Savings Plans are billed as a fixed hourly commitment. AWS allows refunds for Savings Plans with commitments under $100/hour, but refunds are only permitted within 7 calendar days of purchase and within the same calendar month.
Detection
- Review the timing of Savings Plan purchases relative to month-end
- Identify commitment purchases made within the final 7 days of a month
- Assess whether review and validation processes allow sufficient time for correction
Remediation
- Establish an internal cutoff that avoids Savings Plan purchases late in the month
- Incorporate purchase date as a required validation check during commitment reviews
- Plan commitment actions earlier in the month to preserve the full correction window