How to calculate charges when changing subscription details mid-term

Table of contents

• • Basic calculation method
  • Detailed calculation methods
    • For subscriptions via the MagicPod plans page
    • For subscriptions via application form

Basic calculation method

When changing contract details (e.g., adding options or upgrading plans), proportional billing is applied.

Proportional billing means the fee is recalculated based on the remaining duration of the contract period.

Example:

• Original plan: 100 additional test cases ($100/month)
• New plan: 200 additional test cases ($200/month)
• Change timing: Mid-billing period (e.g., mid-month)

Calculation:

1. Unused portion of original plan:

   • -$50 (half of the $100 monthly fee)

2. Remaining portion of new plan:

   • +$100 (half of the $200 monthly fee)

Total additional charge: -$50 + $100 = $50

Detailed calculation methods

The specific calculation method varies depending on how you subscribed.

For subscriptions via the MagicPod plans page

Payments are processed using Stripe's API, which calculates charges on a per-second basis.

If an option is increased within the same category, the entire amount of the previous plan is subtracted before adding the new amount.

Note:

When you change your subscription, Stripe handles:

• Refunding the unused portion of your current plan
• Charging for the remaining period of the new plan

For more detailed information on proration, please refer to Stripe's official documentation.

For subscriptions via application form

Decimal places in calculations are truncated.

If an option is increased within the same category, the difference in the number of options is multiplied by the fee to calculate the amount.

Monthly contracts:

Charges are calculated based on the remaining days until the contract end date.

• Formula: (Remaining days ÷ 31) × Monthly fee

Annual contracts:

Charges consider both the remaining months and days until the contract end date.

• Formula: (Monthly fee × Remaining months) + (Monthly fee ÷ 31 × Remaining days)

Example 1:

• Contract period: April 1, 2024 – March 31, 2025
• Option added: December 28, 2024
• Addition: 2 projects ($100 per project/month)

Calculation:

• Remaining period:

  • Remaining months: 3
  • Remaining days: 4

• Monthly charge for 2 projects: 2 × $100 = $200

• Daily charge: $200 ÷ 31 ≈ $6.45

• Total charge (excl. tax):

  • ($200 × 3) + ($6.45 × 4) = $600 + $25.80 = $625.80

• Tax (10%): $625.80 × 10% = $62.58

• Total charge (incl. tax): $625.80 + $62.58 = $688.38

Example 2:

• Contract period: April 1, 2024 – March 31, 2025
• Option change: March 28, 2025
  • Before: 1 project ($100/month)
  • After: 2 projects ($100 per project/month)

Calculation:

• Remaining period:

  • Remaining months: 0
  • Remaining days: 4

• Daily charge before: $100 ÷ 31 ≈ $3.22

• Daily charge after: $200 ÷ 31 ≈ $6.45

• Total charge (excl. tax):

  • (-$3.22 × 4) + ($6.45 × 4) = -$12.88 + $25.80 = $12.92

• Tax (10%): $12.92 × 10% = $1.29

• Total charge (incl. tax): $12.92 + $1.29 = $14.21