UCC 9-406 Notice of Assignment: Requirements and Debtor Defenses

A notice of assignment under UCC 9-406 is the document that tells an account debtor to stop paying the original creditor and start paying a new party who has acquired the receivable. Until that notice arrives, the debtor can keep paying the original creditor and fully discharge the debt. Once it arrives and meets the statute’s requirements, only payment to the assignee counts. A flawed notice leaves the assignee unable to collect; ignoring a valid one can force the debtor to pay the same debt twice.

What the Notice Must Say

The statutory minimum is short. Under UCC 9-406(a), the notification must state that the amount due or becoming due has been assigned, and it must direct the debtor to pay the assignee going forward.¹ A notice that only announces an assignment without redirecting payment does not shift the debtor’s obligation.

The notice also has to be authenticated by either the assignor or the assignee. Authentication does not require notarization. Sending the notice on letterhead, or on a form bearing the sender’s name, is enough, because the printed name works as a symbol adopted to identify the sender and adopt the record.² For an electronic notice, attaching a digital signature or other electronic symbol to the record with intent to adopt it qualifies.

Beyond the statutory minimum, careful drafters include the full names and contact details for both the assignor and the assignee, plus enough detail to identify the specific accounts, contracts, or invoices covered. That specificity matters because vague notices can be disregarded.

When a Notice Is Ineffective

UCC 9-406(b) identifies three situations where a notice fails to trigger the payment shift, even if the basics are in place:

Vague identification of the assigned rights. If the notice does not reasonably identify the rights being assigned, the debtor can disregard it. A blanket reference to “all accounts” without specifying contracts, invoices, or payment streams leaves the debtor guessing, and the statute does not require guessing.¹
Restrictions on payment intangible sales. Where an agreement between the debtor and the seller of a payment intangible limits the debtor’s duty to pay a third party, and that limitation is enforceable under other law, the notice is ineffective to the extent of the restriction.
Partial payment instructions. If the notice tells the debtor to send less than the full installment or periodic payment to the assignee, the debtor can treat the entire notice as ineffective. That is true even when the assignee received only a slice of the account, another assignee holds another slice, or the debtor knows the assignment is limited.¹

The partial-payment protection matters in practice. Assignors sometimes split receivables among multiple assignees and expect debtors to divide each payment accordingly. Debtors have no obligation to keep those books, and this protection cannot be waived by contract.¹

Delivery and When the Notice Takes Effect

Any usual means of communication works. Certified mail with return receipt is common because it creates a delivery record, but regular mail, courier, and electronic transmission are all acceptable. For electronic delivery, the sender must attach a digital signature or equivalent symbol to the record with intent to adopt it.²

The notice becomes legally effective when the debtor actually receives it. For an individual, that means the moment it comes to their attention. For an organization, it is effective once it reaches the person handling the transaction, or once it would have reached that person if the organization maintained reasonable internal communication routines.³ A company cannot dodge a notice by claiming it sat in the mailroom. If internal routing is sloppy, the notice is still treated as received within a reasonable time after delivery.

Demanding Proof of the Assignment

Getting a payment redirection letter from a stranger reasonably raises suspicion. UCC 9-406(c) gives the account debtor the right to demand reasonable proof that the assignment actually happened.¹ Make the request promptly and in writing to preserve a record. The assignee typically responds with a copy of the signed assignment agreement or the underlying security agreement.

The statute does not fix a specific number of days for either side. It uses the “seasonable” standard, which UCC 1-205 defines as acting within the time agreed upon or, if no time was agreed, within a reasonable time given the circumstances.⁴ A debtor with a payment due in days has more urgency than one whose next payment is months out.

While the request is pending, paying the original assignor still discharges the debt. If the assignee never furnishes adequate proof, the debtor can continue paying the assignor and treat the notice as if it never arrived.¹ Once satisfactory documentation shows up, payments have to redirect immediately.

Where Payments Have to Go After an Effective Notice

After a compliant notice, and after any verification the debtor demanded, the debtor can discharge the obligation only by paying the assignee. Payments to the original assignor no longer count.¹ This is where the real financial risk sits. A debtor who ignores the notice and keeps paying the assignor may end up owing the full amount again to the assignee, with no guarantee the assignor will return the money.

The assignee holds the right to enforce and to sue for any unpaid amounts. Once the debtor pays the right party, though, that specific obligation is fully discharged, regardless of any later dispute between the assignor and the assignee.

Defenses the Debtor Keeps Against the Assignee

An assignment transfers the right to collect; it does not strip the debtor of existing protections. Under UCC 9-404, the assignee takes the account subject to two categories of defenses:

Defenses arising from the original contract. Every term of the agreement between the debtor and the assignor carries over. Breach by the assignor, defective goods, and failure to perform services can all be raised against the assignee, and these defenses survive regardless of when the notice was received.⁵
Unrelated claims that accrued before notice. A separate claim the debtor holds against the assignor, such as money owed from a different transaction, can be raised against the assignee only if it accrued before the debtor received the assignment notification.⁵

There is a hard limit on what these claims can do. They reduce what the debtor owes the assignee. They do not let the debtor recover money affirmatively from the assignee. If the assignor owes the debtor $5,000 and the assigned account is $8,000, the debtor offsets and pays $3,000. The remaining $5,000 has to be pursued against the assignor, not the assignee.⁵

The timing rule creates a hard cutoff. Assignees who send notice quickly limit their exposure to cross-claims that keep accruing between the debtor and the assignor.

Anti-Assignment Clauses Generally Do Not Help the Debtor

Many commercial contracts prohibit assignment without consent. Debtors sometimes point to these clauses to justify ignoring a notice. Under UCC 9-406(d), those clauses are ineffective for assignments of accounts, chattel paper, payment intangibles, and promissory notes.¹ The same rule neutralizes contract provisions that would treat an assignment as a default, breach, or grounds for termination.

The override reaches past private contracts. UCC 9-406(f) applies the same rule to statutes and regulations that restrict assignment or require government consent for the transfer of accounts or chattel paper.¹

Exceptions exist. The override does not apply to the sale of payment intangibles or promissory notes, does not cover health-care-insurance receivables, and separate rules may apply when the account debtor is an individual who incurred the obligation for personal or household purposes.¹

Modifying the Contract After the Assignment

Can the debtor and the original creditor still change the underlying contract once the account has been assigned? Under UCC 9-405, yes, but only in a narrow window tied to notification.

Good-faith modifications to an assigned contract bind the assignee in two situations: when the right to payment has not yet been fully earned through performance, or when it has been fully earned but the debtor has not yet received a notification of assignment under 9-406(a). In either case, the assignee acquires rights under the modified contract. The assignment agreement between assignor and assignee can treat those modifications as a breach by the assignor, giving the assignee a remedy against the assignor even though the modification still binds them.

Once the debtor has received an effective notice and performance is complete, the debtor and the assignor lose the ability to modify the contract in ways that bind the assignee. The assignee’s rights are locked in. That is another reason prompt notification pays off for the assignee: it closes the window during which renegotiation between the assignor and debtor could reduce the value of the receivable.

1
Legal Information Institute (Cornell Law School). UCC 9-406 Discharge of Account Debtor; Notification of Assignment
2
Legal Information Institute (Cornell Law School). UCC 9-102 Definitions and Index of Definitions
3
Legal Information Institute (Cornell Law School). UCC 1-202 Notice; Knowledge
4
Legal Information Institute (Cornell Law School). UCC 1-205 Reasonable Time; Seasonableness
5
Legal Information Institute (Cornell Law School). UCC 9-404 Rights Acquired by Assignee; Claims and Defenses Against Assignee