Debtor Structure and Concentration

Why it matters for underwriting

Debtor concentration determines how much of an insured’s turnover is exposed to the default of a small number of buyers. A well-diversified debtor base spreads risk across many independent obligors, so a single default has limited effect on the loss ratio, whereas a book dominated by a handful of large buyers creates accumulation risk: one insolvency can generate a loss disproportionate to the premium collected. Underwriters use this attribute to structure limits across the portfolio, not just in aggregate.

Capturing the attribute and evidence

Proposal forms ask for the share of turnover generated with the largest buyers, the single largest exposure relative to the credit limit requested, and how the portfolio spreads across sectors and countries. Underwriters verify these figures against the aged debtor listing and a turnover-by-buyer report.

Effect on coverage, premium and conditions

Well-diversified debtor books support broader credit limits and favourable rates, since aggregate exposure per default event is naturally capped. High concentration on few buyers typically results in named-buyer sublimits, tighter individual limits subject to case-by-case underwriting, or conditions requiring ongoing monitoring, and can drive premium loadings where diversification cannot be improved.

Mitigation measures

Insureds can reduce concentration risk by diversifying their customer base across sectors and geographies, setting internal credit limits per buyer independent of the insurance programme, and maintaining strong credit management such as regular reviews and prompt collection follow-up. Where concentration is structurally unavoidable, enhanced monitoring and more frequent reporting help preserve broader cover.