In the United States, ductless mini split systems come in either 110V or 220V. The voltage will depend on the model type and manufacturer. Typically 9k btu and 12k btu units are 110V. All 18k btu and greater models require 220V.
Difference in installation
The voltage will affect how you install the mini split unit. Your house outlet uses 110V and you can draw power directly from your electrical line if your unit is rated for 110V.
For 220V, you will need to run an electrical wire from your main panel. The additional electrical line will increase the cost of a mini split installation due to the added material cost and labor required.
Below is an installation job where we had to run an electrical line the main panel to the ductless mini split. We always cover the electrical line to ensure that it is weather resistant and include an electrical disconnect box for you to safely turn off power to your ductless mini split unit.