SolvedSDLTM60500 | Processing: Misdirected items
From HM Revenue & Customs · Stamp Duty Land Tax Manual
It is important that any land transaction paper return, form SDLT1, and associated supplementary returns, form SDLT2, form SDLT3 and form SDLT4, be forwarded to the address provided in this link for scanning. Please ensure the UTRN is noted on all forms.
If supplementary forms only are received see SDLTM60210.