This letter confirms an increase in our billing rate to [amount per hour; amount per session], effective [date]. It is necessary that we request this increase due to a rise in our the costs of conducting our business. We are faced with an increase in energy costs, payroll, and hazard insurance, along with higher energy and leasing overhead. Attached are two copies of our service agreement and we request that you sign one copy and return it to us indicating your approval of this new rate.
Thank you for your patronage.