Gary DK very kindly provided a solution for naming tabs from the contents of
a cell on a worksheet. A further problem has arisen:

The contents of cell B7 on all 125 sheets provides the name for the sheet
tab. Cell B7 gets its information from a separate master sheet.

When I sort the master sheet (because new entries have been added at the
bottom and need to be arranged according to a ref. code) I get an error
message: Runtime error 1004 Cannot rename a sheet to the same name as another
sheet, a referenced object library or a workbook referenced by Visual Basic.

this is the code:

Option Explicit
Private shname As String

Private Sub Worksheet_Calculate()
If Range("B7").Value < shname Then
shname = [b7].Value
End If
Me.Name = shname
End Sub


Any ideas?