That customer type gibbersh is a greek word that basically means "Wholesale"

("Paid"=
You need [Paid] to refer to the field, it's thinking it's a string right now, also what is the use of this? Is this vba? If/Then would make it simpler, in my opinion.

You also need double double quotes presumably for the customertype if that is a string.

I would write it like this, easier to follow.

If Paid=False Then
'Open Report
ElseIf Paid=True and CustomerType="Wholesale" Then
'Open Report
Else
'Open Report
End If

I tried both ways, it's still giving me errors for both ways

my way I still get syntax error (not the = now, just syntax error)
your way I get error 2162

Your Report name should not be in parentheses and you need to tell Access how the Report should be opened, for example acViewPreview.

I added the preview before you told me, ust forgot to write it there.
Deleted the parenthesis and still getting the same syntax error

IIF([Paid]=False,docmd.OpenReport QuotationR,acViewPreview, IIF([Paid]=True & "AND CustomerType=" & "Χονδρικής", docmd.OpenReport OrderInvoiceR,acViewPreview, docmd.OpenReport ReceiptR,acViewPreview))

IIF([Paid]=False,docmd.OpenReport QuotationR,acViewPreview, IIF([Paid]=True & "AND CustomerType=" & "Wholesale", docmd.OpenReport OrderInvoiceR,acViewPreview, docmd.OpenReport ReceiptR,acViewPreview))

You can't put commands inside an IIF statement like that.

fixed it thanks

yeah I used the If-Else If command