Before raising SaaS prices, which customer examples do you test?

A pricing-change question about testing current monthly, annual, and new customer cases before sending the email.

A price change email looks simple until support starts getting edge cases. I like testing three examples before sending it: new customer, current monthly customer, and annual customer near renewal. If the email cannot answer those three, the pricing rule is probably unclear. What example do you always test before announcing a pricing change?