A Time Retainer is a the type of payment structure where you receive a set dollar amount each period (e.g., each month) for a predictable level of effort of service. Analysis of client financial statements might serve as a good example.

You use a Base Retainer if you aren't able to determine in advance just how much service the client will require. An example: The client has claim to three days of your talent each and every month and you receive $4,500 in exchange. The client pays for the three days whether or not they are used. If more of your time is needed you would then be compensated at an agreed-to daily rate--say, $1500 per day.

An Availability Retainer is a payment structure which provides you with some measure of compensation for reducing your flexibility to make yourself available to the client in the event of a need. That is, the client is guaranteed that you will be available, if needed, for say, two days a month. In exchange, you receive a sum usually equal to 25-30 percent of the value of your time. If your daily rate is $2500, you might receive $10,000 per month just to be available. If you are used, you would either receive $2,500 plus $750, or just the $2,500, depending upon how your contract was written.

An Advanced Retainer is different than the above. It refers to the fact that you receive compensation prior to the delivery of your services. It is also called, by some, a start-up payment.