Former Section 9-318(4) did not apply to a sale of a payment intangible (as described in the former provision, "a general intangible for money due or to become due") but did apply to an assignment of a payment intangible for security. Subsection (e) [Maine cite subsection (5)] continues this approach and also makes subsection (d) [Maine cite subsection (4)] inapplicable to sales of promissory notes. Section 9-408 [Maine cite section 9- 1408] addresses anti-assignment clauses with respect to sales of payment intangibles and promissory notes.

Like former Section 9-318(4), subsection (d) [Maine cite subsection (4)] provides that anti-assignment clauses are "ineffective." The quoted term means that the clause is of no effect whatsoever; the clause does not prevent the assignment from taking effect between the parties and the prohibited assignment does not constitute a default under the agreement between the account debtor and assignor. However, subsection (d) [Maine cite subsection (4)] does not override terms that do not directly prohibit, restrict, or require consent to an assignment but which might, nonetheless, present a practical impairment of the assignment. Properly read, however, subsection (d) [Maine cite subsection (4)] reaches only covenants that prohibit, restrict, or require consents to assignments; it does not override all terms that might "impair" an assignment in fact.

Example: Buyer enters into an agreement with Seller to buy equipment that Seller is to manufacture according to Buyer's specifications. Buyer agrees to make a series of prepayments during the construction process. In return, Seller agrees to set aside the prepaid funds in a special account and to use the funds solely for the manufacture of the designated equipment. Seller also agrees that it will not assign any of its rights under the sale agreement with Buyer. Nevertheless, Seller grants to Secured Party a security interest in its accounts. Seller's anti-assignment agreement is ineffective under subsection (d) [Maine cite subsection (4)]; its agreement concerning the use of prepaid funds, which is not a restriction or prohibition on assignment, is not. However, if Secured Party notifies Buyer to make all future payments directly to Secured Party, Buyer will be obliged to do so under subsection (a) [Maine cite subsection (1)] if it wishes the payments to discharge its obligation. Unless Secured Party releases the funds to Seller so that Seller can