
Create Derived/Child Rates
A derived or child rate is a rate that is based upon another rate. This way, when the base (or parent) rate gets adjusted, the derived rate will automatically follow. To create a derived rate, navigate to Settings > Rates > Rates > + ADD NEW.
Then, click Rate Details.
All other fields are already discussed in this article. There are two options here to choose from—BASED or COPY FROM. BASED will always follow its parent rate. Whenever the parent gets adjusted, the child rate amount will automatically update.
COPY FROM will copy from the selected rate as the amounts are, and then behave as an independent rate, so this is not the option we want to select.
Set this to BASED and then select the rate you want this derived rate plan to follow.
Select plus or minus from the dropdown to determine how different the derived rate will be.
Enter a value in the input field next to the rate selection.

Select the next dropdown to determine whether this will be an amount or percentage difference.
Then determine how you want the rate value to round off from the ROUNDING section.
You can either select Nearest 10 decimals or Nearest full amount.
From here, continue creating your rate as discussed in the base rate article.