會計公司即係會計師公司?

You just check whether this company has a CPA firm. If this is a CPA firm 執業會計師 , there must be some professional accountants holding the practising cetificates issued by the HKICPA. Check if the company has a 師 in the company's name. If yes, CPA firm, if not, XX 會計事務所、會計公司、會計及秘書事務所 / 公司 ... no this word " 師 " then just an ordinary company which anyone can open.
The use of the wordings of CPA(Practising) and 執業會計師 is governed by the Hong Kong law.

你都話咗兩間公司個分別囉：有個「師」同無個「師」。如果你想第日考會計師牌，你在會計公司嘅經驗係唔計嘅─咁即係第日你十年寒窗之後忽然發覺要做多幾年至攞到個牌！無牌公司做數當然無有牌個啲咁守規矩，你第日轉去有牌公司亦會有難度。趁早去學番啲正規嘅嘢好過第日唔湯唔水！
希望幫到你！