10(1)Where there is a gaming machine licence for the time being in force in respect of any premises, the holder may at any time apply to the Commissioners for the licence to be amended under this paragraph, and the proper officer shall, on payment of the additional duty (if any), amend the licence accordingly.
(2)A licence may be amended under this paragraph—
(a)so as to increase the number of machines which are authorised by the licence for the premises in question (whether chargeable at one or more of the rates respectively) ; or
(b)so as to increase the number of machines chargeable at one rate and reduce the number chargeable at another rate ; or
(c)in the case of a licence which authorises only machines chargeable at one rate, so as to authorise a specified number of machines chargeable at another rate.
(3)The additional duty referred to in sub-paragraph (1) above shall be payable only where—
(a)the amount of the duty originally paid on the licence, or
(b)in the case of a licence previously amended under this paragraph, that amount plus any additional duty paid in respect of that amendment,
is exceeded by the amount of duty which would have been payable on the original licence if it had been granted as proposed to be amended; and the amount of the additional duty shall then be the difference between those two amounts, except that where a whole-year licence falls to be amended in pursuance of a late application, that is to say an application made after 31st March immediately preceding 30th September on which it is due to expire—
(i)in the case of a licence which has not previously been amended in pursuance of a late application, the additional duty shall be eleven-twentieths of that difference, and
(ii)in any other case, the additional duty shall be the difference between the additional duty that would be payable if no previous late applications had been made and the additional duty paid on any such applications.
(4)Regulations may make provision with respect to the procedure for amending licences under this paragraph, and any such regulations may include provision—
(a)as to the method of amendment (that is to say, whether it is to be effected by endorsement of the licence, or by the issue of an amended licence, or otherwise howsoever), and
(b)as to the time at which a licence is to have effect as amended.