Create UIView with required padding space and add it to textfield.leftView member and set textfield.leftViewMode member to UITextFieldViewMode.Always
// For example if you have textfield named title
@IBOutlet weak var title: UITextField!
// Create UIView
let paddingView : UIView = UIView(frame: CGRectMake(0, 0, 5, 20))
//Change your required space instaed of 5.
title.leftView = paddingView
title.leftViewMode = UITextFieldViewMode.Always