Why not set the AllowEdits property of the form in the subform as well?
Presumably you want to block deletions as well as edits if it is invoiced,
so something like this:
Private Sub Form_Current()
Dim bLock As Boolean
bLock = Nz(Me.Invoiced, False)
If Me.AllowEdits <> bLock Then
Me.AllowEdits = bLock
Me.AllowDeletions = bLowk
With Me.[Sub1].Form
.AllowEdits = bLock
.AllowDeletions = bLock
End With
End If
End Sub

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Allen Browne - Microsoft MVP. Perth, Western Australia
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> Hi!
>
[quoted text clipped - 16 lines]
> edit records on the subform although not on the main form. What kind of
> procedure is needed for the subform to lock records like the main form?