Doing self assessment first time - Help!

This is the first year I have done my self-assessment. I have realised that I have missed out on some expenses as I didn't realise I could expense them (petrol money when going to inspect my property). I have submitted the form, and now i'm nervous about amending it. Can you pleasw advise and let me know if it is ok to amend and resubmit my tax return. Does this look bad for me?

Hi Sammy1985,
If you have omitted expenses, yes you can then amend your tax return here:
Self Assessment tax returns
Thank you.