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In law, the real party in interest is the one who actually possesses the substantive right being asserted and has a legal right to enforce the claim (under applicable substantive law). Additionally, the "real party in interest" must sue in his own name. In many situations, the real party in interest will be the parties themselves (i.e., plaintiff and defendant).
In California law, when a case goes up on writ of mandate (California's version of mandamus ) the appellant goes first in the case caption on appeal as the petitioner, and the superior court becomes the respondent. The true opponent is then listed below those names as the "real party in interest". This is how a number of famous California cases like Burnham v. Superior Court of California (1990) ended up with such unusual names.
In Michigan law, the real-party-in-interest rule recognizes that litigation should be begun only by a party having an interest that will [ensure] sincere and vigorous advocacy.
When a trustee is a party to a lawsuit, the real party in interest is the beneficiary of the trust. In the United States, Rule 17 of the Federal Rules of Civil Procedure expressly provides that trustees are the real party in interest when it is necessary to sue on behalf of the estate. A beneficiary may sue under these circumstances only when the trustee refuses or neglects to bring suit.
When funds belonging to a party are held on account, but not necessarily in trust, by a financial institution (e.g., a bank checking account is garnished by a third party who claims a valid unpaid debt) the bank is typically sued as nominal defendant. Of course, the real party in interest is the owner of the account, who has an absolute right to intervene and protect his assets.
A trust is a legal relationship in which the holder of a right gives it to another person or entity who must keep and use it solely for another's benefit. In Anglo-American common law, the party who entrusts the right is known as the "settlor", the party to whom the right is entrusted is known as the "trustee", the party for whose benefit the property is entrusted is known as the "beneficiary", and the entrusted property itself is known as the "corpus" or "trust property". With the strategic and legal use of Trusts, individuals can ensure that their children and grandchildren or chosen beneficiaries are able to benefit completely from the inheritance they want them to receive.
Maxims of equity are legal maxims that serve as a set of general principles or rules which are said to govern the way in which equity operates. They tend to illustrate the qualities of equity, in contrast to the common law, as a more flexible, responsive approach to the needs of the individual, inclined to take into account the parties’ conduct and worthiness. They were developed by the English Court of Chancery and other courts that administer equity jurisdiction, including the law of trusts. Although the most fundamental and time honored of the maxims, listed on this page, are often referred to on their own as the 'maxims of equity' or 'the equitable maxims',The first equitable maxim is 'equity delights in equality' or equity is equality Like other kinds of legal maxims or principles, they were originally, and sometimes still are, expressed in Latin.
In property law, title is an intangible construct representing a bundle of rights in (to) a piece of property in which a party may own either a legal interest or equitable interest. The rights in the bundle may be separated and held by different parties. It may also refer to a formal document, such as a deed, that serves as evidence of ownership. Conveyance of the document may be required in order to transfer ownership in the property to another person. Title is distinct from possession, a right that often accompanies ownership but is not necessarily sufficient to prove it. In many cases, possession and title may each be transferred independently of the other. For real property, land registration and recording provide public notice of ownership information.
The doctrine of privity of contract is a common law principle which provides that a contract cannot confer rights or impose obligations upon any person who is not a party to the contract.
A fiduciary is a person who holds a legal or ethical relationship of trust with one or more other parties. Typically, a fiduciary prudently takes care of money or other assets for another person. One party, for example, a corporate trust company or the trust department of a bank, acts in a fiduciary capacity to another party, who, for example, has entrusted funds to the fiduciary for safekeeping or investment. Likewise, financial advisers, financial planners, and asset managers, including managers of pension plans, endowments, and other tax-exempt assets, are considered fiduciaries under applicable statutes and laws. In a fiduciary relationship, one person, in a position of vulnerability, justifiably vests confidence, good faith, reliance, and trust in another whose aid, advice, or protection is sought in some matter. In such a relation, good conscience requires the fiduciary to act at all times for the sole benefit and interest of the one who trusts.
A fiduciary is someone who has undertaken to act for and on behalf of another in a particular matter in circumstances which give rise to a relationship of trust and confidence.
In property law, a concurrent estate or co-tenancy is any of various ways in which property is owned by more than one person at a time. If more than one person owns the same property, they are commonly referred to as co-owners. Legal terminology for co-owners of real estate is either co-tenants or joint tenants, with the latter phrase signifying a right of survivorship. Most common law jurisdictions recognize tenancies in common and joint tenancies.
A constructive trust is an equitable remedy imposed by a court to benefit a party that has been wrongfully deprived of its rights due to either a person obtaining or holding a legal property right which they should not possess due to unjust enrichment or interference, or due to a breach of fiduciary duty, which is intercausative with unjust enrichment and/or property interference. It is a type of implied trust.
United States trust law is the body of law regulating the legal instrument for holding wealth known as a trust.
English trust law concerns the protection of assets, usually when they are held by one party for another's benefit. Trusts were a creation of the English law of property and obligations, and share a subsequent history with countries across the Commonwealth and the United States. Trusts developed when claimants in property disputes were dissatisfied with the common law courts and petitioned the King for a just and equitable result. On the King's behalf, the Lord Chancellor developed a parallel justice system in the Court of Chancery, commonly referred as equity. Historically, trusts have mostly been used where people have left money in a will, or created family settlements, charities, or some types of business venture. After the Judicature Act 1873, England's courts of equity and common law were merged, and equitable principles took precedence. Today, trusts play an important role in financial investment, especially in unit trusts and in pension trusts. Although people are generally free to set the terms of trusts in any way they like, there is a growing body of legislation to protect beneficiaries or regulate the trust relationship, including the Trustee Act 1925, Trustee Investments Act 1961, Recognition of Trusts Act 1987, Financial Services and Markets Act 2000, Trustee Act 2000, Pensions Act 1995, Pensions Act 2004 and Charities Act 2011.
Provident Tradesmens Bank & Trust Co. v. Patterson, 390 U.S. 102 (1968), is a United States Supreme Court decision which clarified the meaning and application of Rule 19 of the Federal Rules of Civil Procedure. In a unanimous decision, the Court reversed the judgment of the United States Court of Appeals for the Third Circuit and held that an automobile owner's interest in a suit against his insurer did not make him an "indispensable party" to that suit under Rule 19. The Court also made clear that Supreme Court precedent predating the enactment of the Federal Rules of Civil Procedure did not create any substantive right in non-parties to be joined in case, as the Court of Appeals had apparently thought.
Boardman v Phipps  UKHL 2 is a landmark English trusts law case concerning the duty of loyalty and the duty to avoid conflicts of interest.
In real estate in the United States, a deed of trust or trust deed is a legal instrument which is used to create a security interest in real property wherein legal title in real property is transferred to a trustee, which holds it as security for a loan (debt) between a borrower and lender. The equitable title remains with the borrower. The borrower is referred to as the trustor, while the lender is referred to as the beneficiary.
Mortgage Electronic Registration Systems, Inc. (MERS) is an American privately held corporation. MERS is a separate and distinct corporation that serves as a nominee on mortgages after the turn of the century and is owned by holding company MERSCORP Holdings, Inc., which owns and operates an electronic registry known as the MERS system, which is designed to track servicing rights and ownership of mortgages in the United States. According to the Department of the Treasury, the Board of Governors of the Federal Reserve, The Federal Deposit Insurance Corporation and the Federal Housing Finance Agency, MERS is an agent for lenders without any reference to MERS as a principal. On October 5, 2018, Intercontinental Exchange and MERS announced that ICE had acquired all of MERS.
Schmidt v Rosewood Trust Ltd UKPC 26 is a judicial decision concerning the information rights of a beneficiary under a discretionary trust. Although the judgment involved a question as to the law of the Isle of Man, the Privy Council's judgment in Schmidt v Rosewood was adopted into English law by Briggs J in Breakspear v Ackland EWHC 220 (Ch).
Constructive trusts in English law are a form of trust created by the English law courts primarily where the defendant has dealt with property in an "unconscionable manner"—but also in other circumstances. The property is held in "constructive trust" for the harmed party, obliging the defendant to look after it. The main factors that lead to a constructive trust are unconscionable dealings with property, profits from unlawful acts, and unauthorised profits by a fiduciary. Where the owner of a property deals with it in a way that denies or impedes the rights of some other person over that property, the courts may order that owner to hold it in constructive trust. Where someone profits from unlawful acts, such as murder, fraud, or bribery, these profits may also be held in constructive trust. The most common of these is bribery, which requires that the person be in a fiduciary office. Certain offices, such as those of trustee and company director, are always fiduciary offices. Courts may recognise others where the circumstances demand it. Where someone in a fiduciary office makes profits from their duties without the authorisation of that office's beneficiaries, a constructive trust may be imposed on those profits; there is a defence where the beneficiaries have authorised such profits. The justification here is that a person in such an office must avoid conflicts of interest, and be held to account should he fail to do so.
Tracing in English law is a procedure to identify property that has been taken from the claimant involuntarily. It is not in itself a way to recover the property, but rather to identify it so that the courts can decide what remedy to apply. The procedure is used in several situations, broadly demarcated by whether the property has been transferred because of theft, breach of trust, or mistake.
Westdeutsche Landesbank Girozentrale v Islington LBC UKHL 12,  AC 669 is a leading English trusts law case concerning the circumstances under which a resulting trust arises. It held that such a trust must be intended, or must be able to be presumed to have been intended. In the view of the majority of the House of Lords, presumed intention to reflect what is conscionable underlies all resulting and constructive trusts.
Foskett v McKeown UKHL 29 is a leading case on the English law of trusts, concerning tracing and the availability of proprietary relief following a breach of trust.
McDonald v Horn  1 All ER 961 is an English trusts law case on pensions, relevant for UK labour law. It enables the beneficiaries of a pension fund to be indemnified for costs in bringing actions for breach of trust, fiduciary duty or the duty of care against the trustees or directors of a pension fund.
Byers v Saudi National Bank EWCA Civ 43 is a decision of the English Court of Appeal in the long running litigation between the liquidators of SAAD Investments Company Limited and various parties relating to the alleged defrauding of the insolvent company by one of its principals.