When a risk exceeds what one insurer will carry alone, two constructions exist and they are constantly confused. Layering stacks tranches that respond one after another. Co insurance divides horizontally: several insurers each take a percentage of the same cover, on the same terms, across its whole extent. A co insurer at fifteen per cent pays fifteen per cent of every euro, from the first to the last, and not the second tranche. That difference looks obvious and it decides who speaks at the time of loss.
The leader is the one that runs the placement. It negotiates the wording, issues the document, collects the premiums, receives notifications and conducts the investigation. The others, the followers, sign a participation line and defer to it. The saving is considerable: an insured deals with one counterpart instead of six, and the six investigate once. But one must see what that saving presupposes, and it is the point this module means to install: each co insurer is bound for its share alone, by a contract binding it to the insured and not to the others. There is no joint liability, there is an addition of six distinct undertakings that a common mandate makes look like one.
The follow clause organises that mandate, and its reach is exactly what disputes are about. In its wide form the follower undertakes to follow the leader on settlement decisions, including the classification adopted and the amount compromised. In its narrow form it follows on the administration of the contract and keeps its own judgment on coverage, that is on whether the loss falls within the cover. Between the two sit intermediate drafts, often a single sentence, making the duty to follow conditional on the leader's decision having been taken in good faith and in accordance with market practice.
One must then understand why a follower objects, because it is almost never bad faith. A leader carrying forty per cent of a risk and maintaining a commercial relationship with the broker does not have the same incentives as a follower at eight per cent that may never see this client again. On a doubtful file the leader may prefer a generous settlement that preserves the relationship, of which it bears forty per cent and makes the others bear sixty. A follower that refuses is not contesting the facts, it is contesting that the decision was taken in the common interest, and that is exactly what the intermediate clause allows it to do.
On political risk that tension runs higher than elsewhere, for a reason peculiar to the subject: classification is a judgment. Deciding that a series of measures amounts to creeping expropriation, and dating it to one day rather than another, is not an observation but an appraisal, on which the policy year and sometimes the very existence of cover depend. A follower may accept every fact and refuse the classification, which is an intellectually tenable position that no technical expert will settle. That is why disputes between co insurers are more frequent here than on risks where a loss is simply observed.
The insured's position in such a disagreement deserves describing, because it is better than it believes. Each co insurer is bound to it directly for its share, so one follower's refusal does not block the others: the insured collects ninety two per cent and pursues the holdout for its eight. What penalises it is not the loss of that fraction but the time, the energy and having to litigate against one insurer while negotiating with the others. Many insureds give way on principle to avoid that cost, and it is precisely what a follower objecting without conviction hopes to obtain.
Two steps reduce that risk and both are taken at inception, not at the loss. The first is to read the follow clause rather than the list of co insurers, and to know whether it bears on settlement or only on administration; a participation table says nothing of that. The second is to check that the participation documents carry no individual reservations, since a follower that signed its line excluding a category of measures has created an eight per cent hole the insured will discover at the loss, and that information does not circulate by itself: it lives with the placing broker.
This module closes on a sentence a professional must be able to say to a committee without hesitating: a co insurance is not one policy with several signatures, it is several identical policies of which only one is administered. While nothing happens, the distinction is invisible. The day the leader has to classify a fact, it is the whole subject.
A 240 million euro political risk policy covers an aluminium plant in Central Asia. It is co insured: leader 40 per cent, four followers at 20, 20, 12 and 8 per cent. The follow clause provides that co insurers follow the leader's settlement decisions, provided they are taken in good faith and in accordance with market practice. Between March 2024 and June 2025, eight administrative measures progressively reduce the insured's control. The leader adopts the classification of creeping expropriation, dates the triggering event to 14 November 2024, and settles at 195 million in February 2026. The 8 per cent follower refuses: it argues that the correct date is 3 March 2025, which would place the loss in the following policy year where its line was different, and that the leader settled high to preserve its relationship with the broker. It had accepted its line without reservation. Where does the insured stand?
The first thing to tell the insured is that it is not blocked, which is what it always wrongly believes in this situation. Each co insurer is bound to it directly for its share: the 92 per cent of the other four, that is roughly 179 million of the 195 million settlement, are due independently of the fifth's refusal, and there is no reason to await the outcome of the dispute before collecting them. The dispute is about 15.6 million, not 195, and that rescaling changes how the file is run. One must then assess the strength of the follower's grounds, and they are not nil. That it accepted its line without reservation does not bar it from objecting, because the clause it signed is not an absolute follow clause: it reserves good faith and market practice, and that is the ground it stands on, not the facts. Its date argument is serious in principle, the classification of creeping expropriation being an appraisal rather than an observation, and the choice of the day control was lost rarely being defensible without argument. Its interest argument is weaker but it weighs: a leader at 40 per cent that settles high makes the others bear 60 per cent of its generosity, and that is exactly the configuration the good faith reservation targets. What seriously weakens its position lies elsewhere, and that is where the insured should press: the 3 March 2025 date suits it, which is not an argument, and it will have to show that 14 November 2024 was untenable on the documents, whereas the leader worked the file with the insured for fourteen months and holds the full chronology. Three steps therefore follow. Collect the 92 per cent without delay and say so in writing, so that time stops running against the insured. Assemble the dating file together with the leader, which serves both and which neither can produce alone. And check with the placing broker whether this follower filed an individual reservation at the renewal where its line changed, since such a reservation would explain everything and does not circulate by itself.
- 01Co insurance divides horizontally: a co insurer at fifteen per cent pays fifteen per cent of every euro, from first to last, and not a tranche.
- 02There is no joint liability but an addition of distinct undertakings that a common mandate makes look like one: one follower's refusal does not block the others.
- 03The follow clause ranges from absolute follow to mere administrative follow, and the intermediate form reserves good faith and market practice, which is the ground of every dispute.
- 04A leader carrying forty per cent that settles high makes the others bear sixty per cent of its generosity: the follower contests not the facts but the common interest.
- 05Classifying a political fact is an appraisal and not an observation, which makes such disagreements more frequent here than elsewhere and settleable by no expert.