Unsold goods accounting for a private ltd

As a private Ltd company, I realize that we are bound to using accrual based accounting. My question is around the expenses incurred on unsold goods: a) Are the purchase value of unsold goods factored in the same year as an expense? OR b) Do we carry forward the unsold goods COGS into the new financial year, and treat as a pro-rated expense accordingly?

Hi,
Thank you for your question. 
HMRC does not provide accounting advice. 
HMRC’s Business Income Manual contains some information about the relationship between tax and accountancy:
BIM31000 - Tax and accountancy
If this guidance does not answer your question, you will need to contact an accountant or financial adviser.
Thank you.