In a push to strengthen member relationships, two Twin Cities credit unions are now offering savings-linked ATM-debit accounts that automatically rounds up differences on purchases.

In separate promotions starting this spring, the $1.3 billion Affinity Plus FCU of St. Paul started “Stash Your Cash,” while the $277 million TopLine FCU of Maple Grove offered “Sum-It-Up” savings transfers.

Just a week after the launch, TopLine said it opened 40 of the accounts and Affinity Plus said it had 300 after its account debut in early May.

Affinity Plus said its program was geared to “help our members achieve their savings goals even when money may be tight.”

Harry Carter, president/CEO of TopLine, said a major objective of the program is to help build relationships with the account representing a means to make savings “completely painless.”

In a formal statement, Carter said “members can build an emergency reserve, create a child's savings or holiday spending account or even sock dollars away in a mad money fund.”

Nic Peterson, vice president of member innovation at Affinity Plus, said the savings transfer idea has been utilized for some months by large banks, including Bank of America and Wells Fargo, “but we haven't seen it among credit unions.”