Billing Preferences per Account

Billing Preferences per Account

Hello,

We are trying to setup Billing Preferences in Zoho Desk to set up a different pricing per account.
We charge different pricing per hour per customer/account.

Account A = 100 per hour
Account B = 125 per hour

In the Billing Preferences in Time Entry in Desk it is not possible to set this up the way we want.

Is there any we can set this up in Desk? Projects and/or Books is not an option.