An encumbrance is a right to, interest in, or legal liability on real property that does not prohibit passing title to the property but that diminishes its value. Encumbrances can be classified in several ways. They may be financial (ex: liens) or non-financial (ex: easements, private restrictions). Alternatively, they may be divided into those that affect title (ex: lien, legal or equitable charge) or those that affect the use or physical condition of the encumbered property (ex: restrictions, easements, encroachments). Encumbrances include security interests, liens, servitudes (e.g. easements, wayleaves, real covenants, profits a prendre), leases, restrictions, encroachments, and air and subsurface rights. Also, those considered as potentially making the title defeasible are encumbrances, e.g. charging orders, building orders and structure alteration.
Hong Kong 
In Hong Kong, there is statutory definition of "encumbrance". In Conveyancing and Property Ordinance (Cap. 219) it reads: ""encumbrance" (產權負擔) includes a legal and equitable mortgage, a trust for securing money, a lien, a charge of a portion, annuity, or other capital or annual sum; and "encumbrancer" (產權負擔人) has a meaning corresponding with that of "encumbrance" and includes every person entitled to the benefit of an encumbrance, or to require payment or discharge thereof".
Other uses 
It is also a term used by colleges and universities to describe limitations placed on a student's account due to late payment, late registration, or other reasons stated by the institution. An encumbrance can prohibit students from registering for classes, affect the release of their transcripts, or delay the reception of their diplomas.
In management accounting, encumbrance is a management tool used to reflect commitments in the accounting system and attempt to prevent overspending. Encumbrances allow organizations to recognize future commitments of resources prior to an actual expenditure.
- Amount expected to spend, but for which there is no legal obligation to spend. A requisition is a typical pre-encumbrance transaction.
- Amount for which there is a legal obligation to spend in the future. A purchase order is a typical encumbrance transaction.
- Amount for which there has been an expenditure of funds. An expenditure is recorded in Commitment Control for both vouchers payable and journal entries.
- ^ Steven H. Gifis, Barron's Dictionary of Legal Terms, 4th edn., s.v. "encumbrance" (Barron's Educational Series, 2008), 169.
- ^ Fillmore E. Galay et al., Modern Real Estate Practice in Illinois, 4th edn. (Chicago: Dearborn Real Estate Education, 2001), 107.