You said the check was written to your customer "and" the financial company. If there was an "and" between the names, then both indorsements are required. In the unlikely event that there isn't, here's a primer on Business & Commerce Code § 3.301 regarding checks written to multiple payees:
*If an instrument is payable to “A or B,†either A or B is the payee and if either is in possession, then that person is the holder and the person entitled to enforce that instrument.
*An instrument payable to “A and B†is governed by the second sentence of subsection (d). The second sentence provides: “if an instrument is payable to two or more persons not alternatively, it is payable to all of them and may be negotiated, discharged, or enforced only by all of them.â€
“If an instrument payable to two or more persons is ambiguous as to whether it is payable to the persons alternatively, the instrument is payable to the persons alternatively.†In the case of ambiguity, persons dealing with the instrument should be able to rely on the indorsement of a single payee. The Uniform Commercial Code Comment gives the example of an instrument payable to “A and/or B†and says that it is treated like an instrument payable to A or B.
*The commentary does not address instruments payable to two payees without a connecting conjunction. Despite the lack of commentary, I believe an instrument payable to two or more payees without a connecting conjunction is probably the most ambiguous of all. Thus, you could apply the third sentence of subsection (d) and treat the instrument like it was payable to A or B, and rely on the indorsement of a single payee. But, on a large item, you might want to get both indorsements to avoid the risk of loss.
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