Can a bank act as a guarantor for its commercial customer's future debt?
For instance, if a third party service provider provides services for the bank customer, can the bank be a guarantor for its customer?
An attorney thought there may be a law that prohibits this.
Thanks for any help

Heard of Letter of Credit? Yes a bank can guarantee the a future debt as you describe.

Banks cannot issue guarantees. They use letters of credit for that purpose, which hopefully are collateralized.

Cashiers Checks are a form of a guarantee also.

Also look at 12 CFR 7.1017. Which states(a) A national bank may lend its credit, bind itself as a surety to indemnify another, or otherwise become a
guarantor, if:
(1) The bank has a substantial interest in the performance of the transaction involved; or
(2) The transaction is for the benefit of a customer and the bank obtains from the customer a segregated
deposit that is sufficient in amount to cover the bank's total potential liability. A segregated deposit under this
section includes collateral:
(i) In which the bank has perfected its security interest (for example, if the collateral is a printed
security, the bank must have obtained physical control of the security, and, if the collateral is a
book entry security, the bank must have properly recorded its security interest); and
(ii) That has a market value, at the close of each business day, equal to the bank's total potential
liability and is composed of:
(A) Cash;
(B) Obligations of the United States or its agencies;
(C) Obligations fully guaranteed by the United States or its agencies as to principal and
interest; or
©2011 Wolters Kluwer. All rights reserved.
2
(D) Notes, drafts, or bills of exchange or bankers' acceptances that are eligible for rediscount
or purchase by a Federal Reserve Bank; or
(iii) That has a market value, at the close of each business day, equal to 110 percent of the bank's total
potential liability and is composed of obligations of a State or political subdivision of a State.
(b) In addition to paragraph (a) of this section, a national bank may guarantee obligations of a customer,
subsidiary or affiliate that are financial in character, provided the amount of the bank's financial obligation is
reasonably ascertainable and otherwise consistent with applicable law.

thank you all- very helpful!