YOU SAID:

A bank can't lend money to itself unless it, too, is also a bank

INTO JAPANESE

銀行も銀行でない限り、銀行は自分自身にお金を貸すことはできません

BACK INTO ENGLISH

Banks cannot lend money to themselves unless they are also banks

INTO JAPANESE

銀行は銀行でもない限り、自分たちにお金を貸すことはできません

BACK INTO ENGLISH

Banks cannot lend money to themselves unless they are also banks