The more accounts you have at a bank, the better interest rates you may get. By Lisa Gerstner, Contributing Editor January 1, 2013 When it’s time to roll over a certificate of deposit, fishing for a higher interest rate is always smart. But before you yank savings out of your current bank, see whether it will offer you a higher rate for being a repeat customer. For instance, Ally Bank recently offered an interest-rate bonus to a customer who renewed a $15,000 six-month CD for 11 months. SEE ALSO: Where to Stash Your Cash Now Some banks offer higher CD rates to customers who maintain multiple accounts. Connexus Credit Union ($5 to join the Connexus Association and $5 to open a savings account) offers members a 1% rate for six months on balances of $10,000 or more (0.5% on balances below $10,000). To earn that rate, you must have a checking account with direct deposit, make ten monthly withdrawals and sign up for e-statements. Digital Federal Credit Union ($10 minimum to become a member of an affiliated service organization) offers an extra 0.25 percentage point on CDs if you have a checking account with direct deposit and have an active loan or credit card account. With a minimum $25,000 deposit, Digital’s 27-month Jumbo Jump-Up Certificate with Relationship Checking pays 1.23%. Keep an eye out for CDs with promotional terms and rates, too. State Farm Bank recently offered a nine-month CD that paid 0.8% with a $500 minimum -- a higher rate than it was offering on its standard CDs with maturities of three years or less. NerdWallet compiles a weekly index of bonus rates on CDs. For more on earning top rates on CDs and other safe places to park cash, see Where to Stash Your Cash Now. This article first appeared in Kiplinger's Personal Finance magazine. For more help with your personal finances and investments, please subscribe to the magazine. It might be the best investment you ever make.