Presumption against Extra-territorial Effect

Law presumes that legislation has effect only within the territory of the State. The presumption was applied in Chemical Bank v McCormack which concerned the making of orders, which purported to have extra-territorial effect, under the Bankers Books (Evidence) Act, 1879 . Carroll J held that, in the absence of clear words supporting an extra-territorial application of the Act, it should not be interpreted as applying outside the jurisdiction. The presumption against extra-territorial effect was also at issue in Keane v An Bord Pleanála, which points out some of the limits to the presumption. The case concerned the interpretation of the Planning Acts. It was argued before the High Court that since the Planning Acts did not have any express extra-territorial effect, the effects which a development had beyond the limits of the territorial seas could not be taken into account in the granting of planning permission. This argument was rejected by Carroll J in the High Court. She held that the concept of the "common good" which was referred to in the long title of the 1963 Act was a broad one, and included the effects which the development would have outside the national territory. She gave the example of sea pollution which might arise from a grant of planning permission. Such pollution would have an effect on the common good and would therefore have to be taken into account in ascertaining whether or not to grant planning permission. In the instant case, the Board could take into account the benefits of the development outside territorial waters, and this should not be equated with extending the operation of a statute beyond the jurisdiction.Statutory Drafting and Interpretation, Consultation Paper on: Plain Language and the Law (LRC CP14-1999) [1999] IELRC 1 (1st July, 1999)
The same was observed by the  Circuit  Court of Virginia. The following was observed in this connection:

"The jurisdiction of the legislature of any state, however, generally is limited to the geographical area governed by that state. Therefore, "legislative enactments apply only to persons or things within the territory over which the enacting legislature exercises jurisdiction."9 Furthermore, as a general rule, the statutory law of a state can have no effect outside the territorial limits of that state, unless it is given effect in a foreign jurisdiction by courtesy or comity. The Supreme Court of Virginia notes that "[s]tatutes derive their force from the authority of the Legislature, and as a necessary consequence their effect will be limited to the boundaries of the State."

Op, Va. Att'y. Gen. 04-080, (2004), 

See Also: it will be presumed ...that a legislative body... did not intend to give its enactments an impermissible extraterritorial operation. 82 C.J.S. Statutes § 310 (1999).  Enacting a statute with an impermissible extraterritorial effect would violate due process. " 

Allstate Ins. Co. v. Hague, 449 U.S. 302 (1981). 
Bennoin's View
 In Bennion's 'Statutory Interpretation ' Fourth Edition, a distinction is drawn between the territorial extent of an enactment and the territorial application of an enactment. At Page 306 of Bennion, it states that an Act does not usually apply to acts or omissions taking place outside its territory. The basic principle is that words of written or unwritten law expressed in general terms are taken to be subject to an implied limitation which confines their effect to the territorial jurisdiction At Page 308, Bennion states 'similarly the territory of a sovereign state may be divided into areas each having a different system of law. 
This principle is also stated in Halsburys 4^th Edition Volume 44(1) at Paragraph 1319 which states: "The person on whom a particular Act is intended to operate are described as the persons to whom it 'applies'. Who these are is to be gathered from the language and purview of the Act, but the  presumption  (the  presumption  of applicability) is that Parliament is concerned with all conduct taking place within the territories to which the Act extends and with no other conduct".

The territorial extent of enactments was also an issue in Serco Ltd v Lawson [2006] UKHL3 where the Lords were considering Section 94(1) of the Employment Rights Act 1996. At Paragraph 6 Lord Hoffman stated:

"The general principle of construction is, of course, that legislation is prima facie territorial. The United Kingdom rarely purports to legislate for the whole world. Some international cases like torture are an exception, but usually such an exorbitant exercise of legislative power would be both ineffectual and contrary to the comity of nations. That is why all the parties are agreed that the scope of Section 94(1) must have implied territorial limits. More difficult is to say exactly what they are".Faulkner & Ors v BT Northern Ireland & Ors [2005] NIIT 3933_01 (24 October 2005) ,URL: http://www.bailii.org/nie/cases/NIIT/2005/3933_01.html ,Cite as: [2005] NIIT 3933_01