HMRC has further guidance on when a trade or profession is carried out on a commercial basis and with a view to profit (further guidance is available at HMRC’s BIM85705).
Mae gan CThEF ganllawiau pellach ynghylch pryd y mae masnach neu broffesiwn yn cael ei gynnal ar sail fasnachol a chyda'r bwriad o wneud elw (mae canllawiau pellach ar gael yn BIM85705 CThEF).