Customers of the bank that failed last Friday are receiving checks from Indymac's conservator, then running into problems trying to deposit the checks elsewhere, the Los Angeles Times reported.
Spokeswoman Olivia Riley of Washington Mutual said the bank had a "check hold policy that takes into consideration a variety of factors."
Washington Mutual was accepting checks from Indymac, she said.
Former Indymac customer Sheryl MacPhee, of South Pasadena, Calif., told the Times the bank would slap an eight-week hold policy on at least a portion of her Indymac check.
"It seems to me that other financial institutions not accepting these checks is only furthering the panic," MacPhee told the Times.
Wells Fargo was also putting a hold on Indymac checks, the report said.
"Wells Fargo does not have any concerns about the official checks that are being issued by Indymac to its customers," spokeswoman Mary Trigg said.
"However, we do have a concern that people could be taking advantage of this situation by creating fraudulent checks," she said.