Burdened with thousands of defaulted mortgage loans, Washington Mutual went out of business as an independent company in September 2008. JP Morgan Chase took over WaMu's liabilities and assets, and took control of the old bank's checking and savings accounts. Washington Mutual account holders found themselves in possession of blank checks carrying the old bank's routing and account numbers, and payees began to wonder: What do I do with this check?

Accounts and Loans

The collapse of Washington Mutual did not result in any losses for bank depositors. Instead, the buyout resulted in checking and savings accounts moving to JP Morgan Chase, which also assumed control of WaMu's mortgages and loans. If you had a debit card issued by Washington Mutual, you could continue to use it. Direct deposits and bill pay continued as before; if you had taken a loan out from the bank, you continued to make monthly payments to the same entity.

Checking Accounts

JP Morgan Chase continued to honor checks written on the old Washington Mutual accounts. If you have checks bearing a Washington Mutual account and routing number, you may continue to use them. If you have been paid with a Washington Mutual check, you can still cash it. Any financial institution will accept WaMu checks, although individual stores and service businesses can reserve the right to refuse payment with a check, and most banks will charge a service fee for cashing another bank's check.

Unfree Checking

Under management by JP Morgan Chase, WaMu checking accounts began conforming to Chase's fee structure in 2011. Washington Mutual customers no longer enjoyed their "free checking" privileges, which is another reason the old accounts are closing and the old checks are fast disappearing. To avoid the monthly fee, checking customers had to keep a minimum average daily balance or have one direct deposit of at least $500 during the month.

Inactive Accounts

As part of the receivership agreement, the Federal Deposit Insurance Corporation took over inactive WaMu accounts, then forwarded those accounts to the state of the account-holder's last known address. If you are holding a check drawn on an inactive account, then the check will be returned if you try to deposit it. You would then have to file a claim against the account's balance, which has legally become "unclaimed property" in the custody of the state.