> ## Documentation Index > Fetch the complete documentation index at: https://help.uninote.ai/llms.txt > Use this file to discover all available pages before exploring further. # How is the fee calculated if I change my plan midway? If you change your plan in the middle of the month, the fee will be calculated on a **pro-rata basis**. ## A. The difference from the change date to the end of the month will be charged on a pro-rata basis. ### Basic Calculation Rules * **Denominator for calculation**: The number of days in the month when the change occurs (e.g., January has 31 days, February has 28 or 29 days) * **Rounding**: If the calculation results in a decimal, it will be **truncated** *** ### In the case of an upgrade (monthly payment) The difference from the change date to the end of the month will be charged immediately. **Example: If you upgrade on May 15** 1. The difference for May 15 to 31 (17 days out of 31) 2. From the following month, the monthly fee for the new plan will apply *** ### In the case of annual payment (fixed update date rule) * The next update date is based on the date when the paid plan was initially contracted. * The update date **does not change** for upgrades made during the term. **Example: If you newly contract an annual plan on January 10** * Initial charge: Pro-rated amount for the first month (21 days out of 31) + lump sum for the remaining 11 months * Next update date: January 1 of the following year (fixed every year on January 1) **Example: If you upgrade your annual plan on May 15** * Charges: Difference for May 15 to 31 + difference for June to December (7 months) * Next update date: Remains January 1 of the following year *** ### Additional Notes * Downgrades and changes to the payment cycle are not reflected immediately and will apply from the next update date (no pro-rata calculation will be performed). *** ### Related Pages * [Are downgrades and changes to the payment cycle reflected immediately?](/en/daungurdoyaisaikurunohasugunisaremasuka)