Well, the subform should automatically be linked to the parent form with the linked fields. So you shouldn't have anything extra that you need to do once the parent form changes, the subform should automatically change. If you get the linked fields set up right.

Hi Richard - the forms play nicely together in every other way, just not when I apply this very useful filter. I agree I must have something wrong, just struggling to find what. I have attached a snip showing the linked fields.

Why are you showing a different form than the first image?
Which one is giving you the problem?

Sorry Kevin - my bad.
Attached below is the form & subform giving me problems.

Could anyone help me with this problem?

You have two subforms in your last screenshot.  Which one has the problem?  On your first screenshot, the green subform is the one that is blank.  Is that the problem?  We need to see its link master/child fields, which you haven't shown.

Kevin, the second screenshot I uploaded was an error as I explained to Kevin Robertson. The very last screenshot is the correct one showing the master and child fields highlighted in yellow in the properties list.
Thanks

Hi Stepehn, can you show us the code behind your filter combo(s) so we can try to see where the disconnect is? Also, try to make sure we can tell which fields, and forms/subforms apply to which control name. As Kevin Yip said, your initial image showed the customer contact information as blank in form view but your shot of the form in design view that has the fields Master/Child relationship highlighted has the order details subform selected. So just want to make sure we're looking at the actual problem.

Don

Wow - I've really messed this one up haven't I - apologies to everyone trying to help.

Private Sub SalesChannelFilterCbo_AfterUpdate()

If IsNull(SalesChannelFilterCbo) Then
        Me.FilterOn = False
    Else
        Me.Filter = "SaleTypeID=" & SalesChannelFilterCbo
        Me.FilterOn = True
    End If
    
End Sub

Next is the result of filtering using the SalesChannelFilterCbo, with the Sales Channel set to "Website Sales". The resultant filtering is correct for the OrderF parent form, but the Customer/Address subform just shows a blank record instead of the linked customer/address details.

Next is the same parent and subform but in design view with the link master field and link child field highlighted.

The CustomerID field in the parent form is visible at the top centre of the form. The CustomerID field in the CustomersubformF is at the bottom of the subform with the red font colour. This field is hidden in view mode.

Requery your Subform

Private Sub SalesChannelFilterCbo_AfterUpdate()

    If IsNull(SalesChannelFilterCbo) Then
        Me.FilterOn = False
    Else
        Me.Filter = "SaleTypeID=" & SalesChannelFilterCbo
        Me.FilterOn = True
    End If
    
    CustomerSubFormF.Form.Requery

End Sub

I have added that line of code Kevin (thanks), but it hasn't made any difference. As soon as I apply the filter with the combo box, the CustomerSudFormF subform goes blank. It remains blank as I move through the filtered records....

Hmm, can you give us a screen shot of the CustomerSubFormF in design view on the data tab. The actual form properties, not the subform (i.e. click the subform control then click the box in the upper left corner so we are seeing form properties, then click data tab)

Maybe something in the subform's form itself is causing a conflict.

here it is Donald

So the filter in that form is looking for something ebay username.

Is that getting set by your combo or is it stuck from something else

Ideally, it the filter for that would be OrderF!CustomerId so that it would match your order form unless that subform is being used in other forms as well that might cause problems

I've done some more digging Donald - I think that filter has got there from a search I did for an eBay customer on a different form (CustomerEntryF), based on the same table (CustomerT).
The search is through a Search Button.
This is the code from the search button:

Private Sub SearcheBayNameBtn_Click()

S = InputBox("Please enter a phrase to search for an eBay Username..", "Enter a Search Phrase", "Search phrase")
    If S = "" Then Exit Sub
    
    Me.Filter = "eBayUserName LIKE ""*" & S & "*"""
    Me.FilterOn = True

End Sub

Should there be a line in the code which clears that search rather than leave it in the form?

If I remove that filter from CustomerSubformF then everything works as it should.
I think I just need to know what code to put where to stop the search filter being left behind in the form and all will be well?
I have a lot of those filter buttons in the database, so will need to correct them all.

Since you're trying to get it to work when the combo box changes, I would just add it there:

Private Sub SalesChannelFilterCbo_AfterUpdate()

If IsNull(SalesChannelFilterCbo) Then
        Me.FilterOn = False
    Else
        Me.Filter = "SaleTypeID=" & SalesChannelFilterCbo
        Me.FilterOn = True
    End If
    
    CustomerSubFormF.Form.Filter = ""

End Sub

Brilliant - seems to work Donald - thanks again.
That's another beer I owe you!