I have deleted a holding XYZ.OTHER, but would now like to reinstate it. However, Sharesight would not allow me to reuse the same Code, instating, providing the RED Error Message… “Code has already been taken. Code is: XYZ”.
Perhaps I need to hard delete the Code XYZ? How do I fix it?
Hi @Aerarium, welcome to the forum! 
With custom investments, while you may delete these through the holding page they will still exist in the background. Under the account settings tab you’ll notice a sub-menu for custom investments, click this.
Here you’ll find the custom investment code, you just need to click this & then click delete and it will remove it completely from your portfolio & you’ll be able to re-use the code 
I know this is an old post, but in case it helps anyone… I’ve found if you delete a portfolio with holdings, then you’ll be stuck. Sharesight will refuse to let you delete the custom investment owing to there apparently still being existing holdings. I’ve reported to support and awaiting a response.