Used HMRC Online System by Mistake as non-UK Resident

Hi, I recently filed a self assessment tax return for the first time and mistakenly used to HMRC online system as a non-uk resident. It wasn't until after filing that I realised I should have used 3rd party software to do this to allow me to submit a SA109 at the same time. The HMRC online system will not allow me to delete the filing that I have made so what should I do now; should I make another filing using 3rd party software? Or can I contact/write to HMRC in someway to advise them of the mistake and have it corrected? Thanks, Rob

Hi,
You will now need to send the SA109 by post to:
HMRC,
PAYE & Self Assessment,
Thank you.