The present Convention shall continue in force indefinitely but either of the Contracting Parties may, on or before 30th June in any calendar year not earlier than the year 1954, give to the other Contracting Party, through diplomatic channels, written notice of termination, provided that such notice of termination may be given in any year before 1954 if there should be any important change in the laws of the other Contracting Party affecting the application of Article XVI. In such event, the present Convention shall cease to be effective:
- (a) In the United Kingdom:
- (1) as respects income tax, for any year of assessment beginning on or after 6th April in the calendar year next following that in which the notice is given;
- (2) as respects surtax, for any year of assessment beginning on or after 6th April in the calendar year in which the notice is given; and as respects profits tax, in respect of the following profits:
- (i) profits arising in any chargeable accounting period beginning on or after 1st April in the calendar year next following that in which the notice is given;
- (ii) profits attributable to so much of any chargeable accounting period falling partly before and partly after that date as falls after that date;
- (iii) profits not so arising or attributable by reference to which income tax is chargeable for any year of assessment beginning on or after 6th April in the next following calendar year;
- (b) In Norway:
- (1) for the taxable years beginning on or after 1st January in the calendar year next following that in which the notice is given.
DONE at London, in duplicate, in the English and Norwegian languages, both texts being equally authoritative, on the 2nd day of May, 1951.