A system that facilitates masked data entry in an edit control is provided. More particularly, the invention can include a mask engine component that facilitates determination of a valid character from an input of one or more characters with respect to a defined format. In other words, the mask engine can compare an input character to a predefined acceptable format. An interface component that facilitates employment of the mask engine with disparate types of edit controls is also provided. The subject invention can isolate masking functionality as a service that can be interfaced into any desired edit control. For example, the masking service can be interfaced into controls including, but not limited to, a text box, a combo box, a rich edit, a list view and a cell in a data grid or the like.