Pro tanto is a Latin phrase meaning “to that extent” or “for so much,” and in law it describes a partial payment that reduces a larger obligation by the exact dollar amount paid, with the remainder still enforceable. You will see it most often in three settings: a co-defendant settles a lawsuit before trial, the government deposits an estimated value when it takes property by eminent domain, or a debtor makes a partial payment toward a court judgment. In each case the logic is the same. Credit what was paid. Enforce what remains.
A simple example makes it concrete. A court enters a $200,000 judgment, the defendant pays $50,000, and that $50,000 is credited pro tanto. The plaintiff still has the right to collect the other $150,000. The payment neither erases the obligation nor signals agreement about the full amount owed. It satisfies that specific chunk and nothing more.
Pro Tanto Credits in Multi-Defendant Lawsuits
The most contested use of pro tanto arises when one defendant settles before trial and the others go to verdict. The question is how much credit the non-settling defendants get for that earlier settlement. Under the pro tanto method, the answer is dollar-for-dollar. If a plaintiff settles with Defendant A for $20,000 and later wins a $76,898 judgment against Defendant B, the judgment against B is reduced by exactly $20,000, leaving B responsible for $56,898.
That example comes from Ex parte Goldsen, a case involving two defendants liable for injuries from a car accident. The court offset the second defendant’s judgment by the precise amount of the first defendant’s settlement. Dollar-for-dollar reduction is the hallmark of pro tanto credit, and it remains the default in many state courts for tort cases.
The Proportionate Share Alternative
Pro tanto is not the only method. A competing approach, proportionate share credit, reduces the judgment by the settling defendant’s percentage of fault instead of by the settlement dollars. The U.S. Supreme Court adopted the proportionate share rule for federal admiralty cases in McDermott, Inc. v. AmClyde, reasoning that it better prevents windfalls and discourages strategic low-ball settlements.1Legal Information Institute. McDermott Inc v AmClyde, 511 US 202 (1994)
The difference between the two methods can swing a case by tens of thousands of dollars. Say a jury finds Defendant A 60% at fault and Defendant B 40% at fault, with total damages of $100,000, and A settled early for $10,000. Under pro tanto credit, B’s liability drops from $100,000 to $90,000, so B ends up paying for A’s bargain settlement. Under proportionate share credit, the court reduces the judgment by A’s 60% share ($60,000), and B owes only $40,000. The plaintiff, not B, absorbs the risk of settling cheaply.
Which method applies depends entirely on your jurisdiction and the type of case. Many state courts still use pro tanto as their default; some use it for certain categories and apply proportionate share to others.
Pro Tanto in Eminent Domain
Pro tanto plays its most structured role in condemnation. The Fifth Amendment forbids the government from taking private property for public use without just compensation,2Constitution Annotated. Amdt5.10.1 Overview of Takings Clause but the government and the owner rarely agree on what “just” means. A pro tanto deposit bridges that gap while litigation continues.
Under the Declaration of Taking Act, the federal government acquires property immediately by filing a declaration of taking and depositing its estimated compensation with the court. Title transfers to the government as soon as the deposit is made.3Office of the Law Revision Counsel. 40 US Code 3114 – Declaration of Taking The property owner can apply to the court for release of some or all of the deposited funds. Withdrawing those funds does not waive the owner’s right to argue the property is worth more. The Department of Justice instructs its own attorneys to notify landowners that funds are available for distribution “without prejudice to the right of the landowner to claim a larger amount.”4U.S. Department of Justice. Justice Manual 5-15.000 – Land Acquisition Section
Interest rules give both sides a reason to move. Once the government deposits its estimate, interest generally stops running on the deposited amount. If the court later determines the property was worth more, the owner can recover interest on the difference between the final award and the pro tanto deposit. A lowball deposit followed by years of litigation can produce substantial interest on the shortfall. On the deposited portion, the government pays none.
Owners who prevail in federal condemnation cases can also recover reasonable litigation costs, including attorney, appraisal, and engineering fees, when the government abandons the proceeding, loses the case, or a court enters judgment for the plaintiff in a suit claiming compensation for a federal taking.5Office of the Law Revision Counsel. 42 US Code 4654 – Litigation Expenses
How Partial Payments Affect Interest
In federal court, interest on a money judgment runs from the date of entry at a rate pegged to the weekly average one-year constant maturity Treasury yield for the week before judgment, compounded annually.6Office of the Law Revision Counsel. 28 US Code 1961 – Interest A pro tanto payment reduces the principal on which that interest continues to accrue. If a $500,000 judgment is partially satisfied by a $200,000 payment, interest from that point runs on $300,000, not the original balance.
Timing matters. A defendant who delays partial payment keeps interest accruing on the full amount. A plaintiff who accepts partial payment early loses the leverage of a larger interest-generating base. State courts have their own interest statutes, but the principle holds everywhere: partial payment reduces the accruing base.
Getting a Partial Payment Recorded by the Court
Partial payments don’t reduce a judgment on their own. Someone has to ask the court to recognize that part of the judgment has been satisfied. In federal court, a party can move for relief from a judgment under Rule 60(b) on the ground that it has been partially satisfied or discharged.7Legal Information Institute. Federal Rules of Civil Procedure Rule 60 – Relief from a Judgment or Order Enforcement of money judgments otherwise follows the procedure of the state where the federal court sits, unless a federal statute says otherwise.8Legal Information Institute. Federal Rules of Civil Procedure Rule 69 – Execution
In practice, the defendant submits the payment with documentation identifying the case and the judgment. The clerk records the payment in the case file, updating the satisfied amount and the remaining balance. Both sides have reasons to make sure this paperwork is clean. The defendant needs a record showing what was paid and when, to prevent double collection. The plaintiff needs the record to preserve enforceability of the unpaid balance and to establish the correct principal for ongoing interest. Sloppy documentation turns into drawn-out disputes over what’s still owed.
The Accord and Satisfaction Trap
Accepting a pro tanto payment sounds safe because the whole premise is that it covers only part of the debt. It isn’t always safe. If the paying party writes “payment in full” on the check or encloses a letter saying the payment is intended as full satisfaction, cashing the check can legally extinguish the rest of the debt. That doctrine is called accord and satisfaction.
Under UCC Section 3-311, a claim is discharged when the debtor tenders an instrument in good faith as full satisfaction of a disputed or unliquidated claim, the check or accompanying communication conspicuously states that it is tendered as full satisfaction, and the creditor obtains payment on it.9Legal Information Institute. UCC 3-311 – Accord and Satisfaction by Use of Instrument The claim must be genuinely disputed or unliquidated, and the full-satisfaction language must be conspicuous. If both are true, depositing the check can end the right to collect anything more.
Two narrow escape hatches exist. An organization that has already sent the debtor a conspicuous notice directing dispute-related payments to a designated person or office can avoid discharge when the check is sent elsewhere. Any creditor can also undo the accord by tendering repayment of the check amount within 90 days after cashing it.9Legal Information Institute. UCC 3-311 – Accord and Satisfaction by Use of Instrument Outside those exceptions, the discharge sticks. Before cashing any partial payment, read every word on the check and any attached correspondence. If anything suggests the payment is tendered as full settlement of a disputed amount, talk to an attorney before depositing it.
Pro Tanto vs. Pro Rata
These two Latin phrases get mixed up constantly, and they describe different calculations. Pro tanto means “to that extent” and reduces an obligation by a specific dollar amount. Pro rata means “in proportion” and divides an obligation into shares based on each party’s relative stake.
In a multi-defendant tort case, a pro tanto credit reduces the judgment by exactly what the settling defendant paid. A pro rata approach would instead divide total damages by the number of defendants regardless of what any one of them paid. If three defendants are jointly liable for $300,000 and one settles for $50,000, the pro tanto credit is $50,000. A pure pro rata credit would be $100,000 (one-third of the total), even though the settling defendant paid half that.
In bankruptcy and creditor distribution, pro rata takes on a different sense: each creditor receives a share of available assets proportional to the size of their claim. A debtor with $60,000 in assets and three creditors owed $40,000, $30,000, and $30,000 pays each creditor 60 cents on the dollar. That is pro rata distribution. A pro tanto payment, by contrast, satisfies part of a single creditor’s claim by a fixed amount, independent of what anyone else receives.
The shortest way to keep them straight: pro tanto is subtraction, pro rata is division.