Whenever any person required to pay a tax under this chapter quits business or otherwise disposes of his business, any tax payable hereunder shall become immediately due and payable and such person shall immediately make a return and pay the tax due, and, if such tax is not paid by said person within 10 days from the date of such sale, exchange or disposal, said purchaser or successor shall likewise thereupon become liable for the payment of the full amount of such tax. [Ord. 8924 § 12, 1981].