Definition
Latin: "with the burden." A term of conveyancing and property law expressing that a transfer of property carries with it any existing encumbrances, charges, or obligations attached to that property. A party who takes property cum onere receives it subject to whatever burdens already run with it — liens, easements, covenants, mortgages, or other incumbrances — and cannot claim the rights of a purchaser free of those burdens.
The principle is captured in two related maxims drawn from the Roman law sources preserved in the Digest:
Transit terra cum onere — the land passes with the burden.
Res transit cum suo onere — the thing passes with its burden or charge.
Together these maxims express the same idea: the transferee steps into the position of the transferor with respect to obligations that run with the property itself, not merely obligations personal to the prior holder.
Why It Matters in Research
The term appears most frequently in older equity and real property materials, particularly those dealing with notice, priorities, and the rights of purchasers. Researchers examining 19th-century conveyancing disputes will encounter cum onere in discussions of whether a buyer had actual or constructive notice of an incumbrance — because notice is often the hinge on which the doctrine turns. A bona fide purchaser without notice may take free of certain equitable charges; one who takes with notice takes cum onere.
In admiralty materials, the phrase also appears in prize law contexts. Burrill cites Sir William Scott's admiralty opinions (4 Rob. Adm. R. 317, 347), where the phrase described a captor taking a vessel subject to existing obligations — a distinct usage researchers should not conflate with the property-law sense.
The companion maxim cum par delictum est duorum (when both parties are in equal fault, the possessor's cause is preferred) sometimes appears alongside cum onere in historical sources, but it is a separate legal principle addressing fault allocation rather than encumbrance. Be alert to historical dictionaries bundling these together, as Black's and Rapalje & Lawrence both do, which can mislead researchers into treating them as a unified doctrine.
Modern research tools may not index this term directly. Researchers should search variant forms: the English translation "with the burden," the related maxims transit terra cum onere and res transit cum suo onere, and the concept of "taking subject to" an encumbrance, which is the contemporary functional equivalent.
Historical Dictionary Support
The four historical sources are in close agreement on the core meaning. All define cum onere as "with the burden" and apply it to the transfer of property subject to existing charges or incumbrances. The sources converge on notice as the operative condition: Rapalje & Lawrence explicitly frames it as applying to a purchaser "who has knowledge or notice of a charge or incumbrance."
Burrill provides the most substantive development, citing Powell on Devises, Coke on Littlefield (Co. Litt. 231a), and Bracton (fol. 47b, 48), giving the term its deepest roots in the common law treatise tradition. The Bracton and Coke citations anchor the principle firmly in medieval English real property law, tracing through the Roman law maxims of the Digest.
Black's (both editions) and Rapalje & Lawrence append the cum par delictum maxim from Digest 50.17.154 without explaining its separate function. Burrill, by contrast, keeps the term's treatment focused on the encumbrance principle. Researchers relying solely on Black's may initially read the fault-allocation maxim as part of the cum onere doctrine rather than recognizing it as an incidentally grouped civilian maxim.
No historical source addresses the admiralty application with any depth beyond Burrill's brief citation to Sir William Scott. Modern admiralty treatises should be consulted for that strand independently.
Jurisdictional Note
As a Latin maxim rooted in common law and civilian sources, cum onere has been applied across common law jurisdictions without meaningful definitional variation. Practical differences arise in how jurisdictions treat constructive notice and bona fide purchaser protections under modern recording acts — those statutory frameworks govern when the doctrine applies in contemporary American practice, and they vary by state.