Try this

Code:
With Worksheets("Rates Matrix")
        .Range("I5:M5").Insert (xlDown)
        .Range("I5").Value = AddSupplier.TextName.Value
        .Range("J5").Value = AddSupplier.TextFuel.Value
        .Range("K5").Value = AddSupplier.Text20ft.Value
        .Range("L5").Value = AddSupplier.Text40ft.Value
        .Range("M5").Value = AddSupplier.Text40hc.Value
        'FILTER THE TABLE A - Z TO PUT NEW SUPPLIER IN ORDER
        .AutoFilterMode = False
        .Range("I2:I" & .Cells(.Rows.Count, "I").End(xlUp).Row).Sort Key1:=.Range("I2"), Order1:=xlAscending, Header:=xlYes
    End With