We are all aware that a document,  falling within the description in  Schedule I of the Maharashtra Stamp Act,(the “Act”)  and which is executed within the State of Maharashtra, is liable to be stamped at the rates stipulated in the said Schedule.
But even documents executed outside the state and duly stamped as at the place of execution, which pertain to any property situate, or to any matter or thing  done or to be done in the state and received in the state,are liable to be stamped  (See Section 3(b) ). The differential between the amount already paid on the instrument, and the duty leviable in Maharashtra, is required to be paid (Section 19),  within  three months after the date on which it is first received in the state(Section 18)  There is a corresponding similar provision in the Indian Stamp Act, which will be relevant in states where that statute applies.
So when determining the stamp duty payable on a document, it is not just the state  where it is first executed which is relevant, but also whether the document affects any property situated within Maharashtra or needs any matter or thing to be done in this state. A document which is not properly stamped cannot be admitted in evidence or acted upon, registered or authenticated unless the proper stamp duty has been paid.(Section 34)
This issue becomes important in cases where the stamp duty prescribed for a particular document in Maharashtra is higher than in another state, particularly where, at first glance, there is nothing significant to be done within the state. So for example, the Bombay High Court has had to consider the question in cases where a loan is taken outside the state, and all documentation including debenture trust deed for immovable property executed outside the state, but the immoveable property is situated in the state. In such a case, whenever the documents are brought into the state, they will be liable to be stamped with the differential duty leviable under the Maharashtra Stamp Act., within three months after they were first brought in. This issue also needs to be understood in relation to execution of documents involving transfer of Intellectual Property.
In a recent set of cases in the Bombay High Court, this question has been considered in the context of petitions filed under sections 9 and 11 of The Arbitration and Conciliation Act. In these cases, financing documents such as loan agreements, guarantees, etc. were executed outside the state, duly stamped as at the place where they had been executed, but prescribed arbitration in Mumbai. When such documents, or their copies, were brought into the state for instituting arbitration proceedings, or for being relied upon as evidence in legal proceedings in Mumbai , the Court had to consider whether  the matters could  go forward without first paying the differential stamp duty on the documents which contained the arbitration agreement? In June 2013,in  the case of Lakdawala Developers Pvt Ltd vs Badal Mittal and ors, Justice Chandrachud heading the  Division Bench held that as the document under review was not stamped, the arbitration clause in it could not be given effect to unless the document was properly stamped. Justice Chandrachud relied on the judgement of the Supreme Court in SMS Tea Estates Pvt. Ltd. Vs. Chandmari Tea Co. Pvt.Ltd. 2011(4)-Arb.L.R. - 265(S.C.) ( a case under the Indian Stamp Act)  which held that, “Having regard to Section 35 of the Stamp Act, unless the stamp duty and penalty due in respect of the instrument is paid, the court cannot act upon the instrument, which means that it cannot act upon the arbitration agreement also which is part of the instrument. ... ... ....."
In a subsequent case however, in October 2013,Justice R.D.Dhanuka of the Bombay High Court held, in Aditya Birla Finance Limited vs Coastal projects Limited, that interim relief under section 9 and 11 of the Arbitration Act could be granted, even in cases where the arbitration clause was contained in a document which was not properly stamped. He distinguished this case from Lakdawala on the basis that the petitioners in Aditya Birla, still had time to pay the stamp duty, as the three month time limit after the document was received in the state had not expired, and further, that since the respondent was contractually bound to pay the duty and had not paid it, he could not take advantage of his own default. 
The issue is thus still not settled and is currently being litigated in the case of Tata Capital Fiancial Services  Ltd. Vs Ruchira Autolinks (P) Ltd & Others, which is currently pending in the Bombay High Court.
For practitioners therefore, it is important to be aware of the applicable stamp duty in states where the document is executed, as well as those where the property is located, or where something needs to be done pursuant to the document.