Data sort a dynamic range?

[roxnoxsox]

I'm trying to write a macro which will data sort a dynamic range. The number of columns will always be the same (A:N) but the number of rows will change.

So I want to start at row 4 and sort all data from here down, based on the contents of column N. I don't have any headers.

Here is what I managed to record but I'm not sure how this should be changed to fit my range?

Sub TestMacro()


    Rows("4:274").Select
    ActiveWorkbook.Worksheets("Sheet1").Sort.SortFields.Clear
    ActiveWorkbook.Worksheets("Sheet1").Sort.SortFields.Add Key:=Range("N4:N274") _
        , SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:=xlSortNormal
    With ActiveWorkbook.Worksheets("Sheet1").Sort
        .SetRange Range("A4:N274")
        .Header = xlGuess
        .MatchCase = False
        .Orientation = xlTopToBottom
        .SortMethod = xlPinYin
        .Apply
    End With
End Sub

Many thanks in advance

[Bob Phillips]

Sub TestMacro()
Dim lastrow As Long

    With ActiveWorkbook.Worksheets("Sheet3")
    
    
        lastrow = .Cells(.Rows.Count, "N").End(xlUp).Row
        .Sort.SortFields.Clear

        .Sort.SortFields.Add Key:=.Range("N4").Resize(lastrow - 3), _
                             SortOn:=xlSortOnValues, _
                             Order:=xlAscending, _
                             DataOption:=xlSortNormal
        .Sort.SetRange .Range("A4:N4").Resize(lastrow - 3)
        .Sort.Header = xlNo
        .Sort.MatchCase = False
        .Sort.Orientation = xlTopToBottom
        .Sort.SortMethod = xlPinYin
        .Sort.Apply
    End With
End Sub

[roxnoxsox]

Perfect, thank you!