What it means
Banking's oldest prudential rule is simple: do not bet the bank on one customer. Legal lending limits put a number on it, capping loans to any single borrower at a percentage of the bank's capital.
In the United States, the framework sits in federal law and regulation: as a rule of thumb, a national bank may lend up to 15% of its capital and surplus to one borrower unsecured, plus a further 10% against certain collateral. A loan above the limit is an excess loan, and it is a violation even if the borrower is flawless, because the offence is concentration, not credit quality.
Other jurisdictions express the same idea through large-exposure rules: under the EU framework, an exposure to a single client or connected group may not exceed 25% of a bank's eligible capital. The logic is arithmetic survival, since if one borrower owes 30% of a bank's capital and fails, the loss can erase nearly a third of the cushion that protects depositors, from a single default.
Connected borrowers count together, so a group of companies under common control is treated as one exposure, which is where honest banks get caught: five small loans to five subsidiaries can add up to one excess loan. The rules also shape deal-making, since large corporate loans are routinely syndicated, split among many banks, precisely so no single lender breaches its limit.
Banks manage the ceiling with participations, syndications and guarantees, selling pieces of large loans to other lenders while keeping the client relationship. For a business owner, lending limits explain a common mystery: why a loyal bank, happy with the relationship, declines to grow a facility and instead brings in a partner bank.
The constraint is legal, not personal. Knowing your banker's limit is practical intelligence, so a growing company should ask early where its borrowing sits relative to the bank's single-borrower ceiling, before a crucial expansion depends on an answer.
Excess loans still happen, usually through oversight: capital shrinks in a bad year and a previously compliant loan drifts over the line, or related borrowers are missed. When regulators find them, the response is escalation, including immediate reduction plans, increased supervisory attention and, in serious cases, enforcement action against the bank and its officers.
The concept generalises beyond banking, since any lender, factor or lessor funding itself with finite capital faces the same concentration arithmetic, even without a statute. The enduring lesson is that concentration limits protect both sides: the bank from one default, and the borrower from a lender whose troubles would otherwise become its own.
In practice
Real-world examples.
Example
A bank with $100 million of capital and surplus may lend one borrower about $15 million unsecured under the US rule of thumb. A request for $30 million forces the bank to syndicate part of the loan or decline. The borrower is introduced to partner lenders rather than refused outright.
Example
Five subsidiaries of one group borrow $4 million each, and the regulator reads the loans as a single $20 million exposure. Against $100 million of capital that is 20%, above the 15% unsecured limit. The bank must reduce the exposure or secure it with qualifying collateral.
Example
A growing manufacturer is introduced to a second bank because its facility approaches its main bank's legal ceiling. The two banks share the facility, and the manufacturer gains a second banking relationship. Its expansion proceeds without a sudden funding squeeze.
Formula
Calculation
US rule of thumb: single-borrower limit = 15% of capital and surplus unsecured, plus up to 10% more with certain collateral. EU large-exposure cap: 25% of eligible capital per client or connected group.
Worked example. A fictional bank has $100,000,000 of capital and surplus.
- Unsecured limit = 15% x $100,000,000 = $15,000,000.
- Additional limit against certain collateral = 10% x $100,000,000 = $10,000,000, giving up to $25,000,000 in total.
- Under the EU-style cap, 25% x $100,000,000 = $25,000,000 for a single client or connected group.Case study
Seen in the real world.
Fictional example: Dunmore Agri Holdings, a fictional farm group, borrowed from one regional bank through four operating subsidiaries. Each loan was modest; together they reached 28% of the bank's capital after a year of losses shrank that capital. The regulator flagged an excess concentration, and the bank had to reduce exposure quickly, forcing Dunmore into a rushed refinancing in a poor market. The group's new finance head thereafter tracked its lenders' capital as carefully as its own, and split facilities across two banks before the next expansion.
Watch out
Common mistakes.
- Thinking a good borrower makes an excess loan acceptable, when the violation is concentration and regulators cite it regardless of credit quality.
- Missing connected-borrower aggregation, when subsidiaries and related parties count as one exposure.
- Assuming only the bank cares, when a borrower dependent on a bank near its limit can face a sudden funding squeeze.
Questions
People also ask.
What exactly is an excess loan?
A loan, or aggregated exposure to one borrower or connected group, that exceeds the bank's legal lending limit, typically a set percentage of the bank's capital. It is a regulatory violation even when the borrower is paying on time.
What are typical lending limits?
In the US, roughly 15% of capital and surplus unsecured plus 10% more against certain collateral for national banks, with similar state rules. The EU caps large exposures at 25% of eligible capital, and the exact limits are set by the regulator, so check the current rules.
Why does my bank want to syndicate my loan?
Often because your facility is approaching its single-borrower ceiling. Syndication lets it keep the relationship while sharing the exposure, and for you it builds a second banking relationship before you urgently need one.
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