I'm trying to add/remove command bar in code. It is created fine, but
persists after workbook is closed.

In ThisWorkbook code I have:

Sub Workbook_Open()
Call BuildToolBar
End Sub
Sub Workbook_Close()
Call RemoveToolBar
End Sub

In code module, I have:

Sub BuildToolBar()
Dim cb As CommandBar
Dim cbcCommandBarButton1 As CommandBarButton
Dim cbcCommandBarButton2 As CommandBarButton

'delete commandbar if it exists
On Error Resume Next
Application.CommandBars.Item("Prep Actual Costs").Delete
On Error GoTo 0

'create new commandbar
Set cb = Application.CommandBars.Add(Name:="Prep Actual Costs",
Position:=msoBarTop)
Set cbcCommandBarButton1 = cb.Controls.Add(Type:=msoControlButton)
With cbcCommandBarButton1
.Caption = "&Prep Actuals"
.OnAction = "'" & ThisWorkbook.Name & "'!PrepActuals"
.FaceId = 2950
.Style = msoButtonIconAndCaption
End With

Set cbcCommandBarButton2 = cb.Controls.Add(Type:=msoControlButton)
With cbcCommandBarButton2
.Caption = "&Show Labor Lookup"
.OnAction = "'" & ThisWorkbook.Name & "'!ShowLaborLookup"
.FaceId = 19
.Style = msoButtonIconAndCaption
End With

cb.Visible = True
End Sub
Sub RemoveToolBar()
On Error Resume Next
Application.CommandBars("Prep Actual Costs").Delete
End Sub