Excess liability insurance UK: building layers above your primary cover

What an excess layer actually is

An excess liability policy, sometimes called an excess of loss or umbrella layer, is a second policy that sits directly above your primary liability cover. It has an attachment point, which is the level at which it starts to respond. If your primary public liability policy carries a limit of £10m and your excess layer provides a further £10m above it, you have a £20m programme. The excess insurer pays nothing until the primary limit has been properly exhausted by a covered claim.

The important word there is covered. An excess layer is not a general promise to pay large losses. It responds to the claim as defined by its own wording, above the limit beneath it. That is why the relationship between the two wordings matters more than anything else on the schedule.

Why contracts demand limits your primary insurer will not write

Most firms first meet excess layers through a contract. Construction frameworks, rail and infrastructure work, local authority tenders, landlord licences and principal contractor requirements routinely ask for public liability limits well above what a standard package policy provides. Some ask for £10m, some for £20m or more, and the requirement is usually non-negotiable if you want the work.

Primary insurers cap the capacity they will deploy on any one risk. When the contract asks for more than your insurer will give, the answer is not to switch insurer endlessly in search of a bigger number. It is to layer: keep a strong primary policy and buy the additional limit above it from one or more excess insurers.

Follow-form versus standalone wordings

A follow-form excess layer adopts the terms, conditions and exclusions of the primary policy beneath it, subject only to its own limit and attachment point. This is what you want in most cases, because it means the tower behaves as one consistent block of cover. If the primary pays, the excess pays once the primary is exhausted.

A standalone excess wording has its own terms, and this is where programmes quietly go wrong. If the excess layer carries an exclusion the primary does not, then for that peril your cover stops at the primary limit, however tall the tower looks. A layer that is cheaper because it is narrower is not a saving; it is a gap positioned precisely where you told the market you needed protection. Before we place any layer, we read it against the primary line by line.

How layers respond in sequence

A layered programme pays vertically. The primary insurer handles the claim, appoints lawyers and pays first. Once its limit is exhausted, the first excess layer attaches, then the next, in order. Each layer only ever pays the slice of the loss that falls within its band.

Two practical points follow. First, notify every layer of a serious claim early, not just the primary insurer; excess wordings carry their own notification conditions and a late notification can prejudice the very layer you need. Second, check how defence costs are treated at each level, because a layer that handles costs differently from the primary changes how quickly the tower erodes.

Aggregate erosion: the limit that shrinks during the year

Public liability limits usually apply per occurrence, but products liability and some other covers are written on an aggregate basis, meaning one limit for all claims in the policy year. Earlier claims erode the aggregate, and because the excess layer attaches above the primary limit, erosion below can drag the whole tower down with it.

If your primary products aggregate has been partly spent by mid-year, your real headroom is smaller than the schedule suggests. On risks with genuine claims activity we look at reinstatement provisions and at how each layer defines exhaustion, so a bad year does not leave you exposed for its final months.

Layered programme or one big limit from a single carrier?

Where one insurer will write the whole limit, a single policy is simpler: one wording, one claims team, no arguments between layers about who pays what. For modest uplifts above a package policy, that is often the right answer.

Layering earns its keep when the limit required is beyond single-carrier appetite, or when spreading the risk across insurers produces a better structure overall. The cost of that flexibility is coordination, which is the broker's job: matching wordings, aligning renewal dates, and making sure every layer sees the claims it may one day have to pay. Employers' liability has its own floor here too; the statutory minimum is £5m, most insurers issue more as standard, and some contracts ask for limits above even that.

Before you sign the contract, not after

The best time to design a liability tower is while the contract is still negotiable. Bring the insurance clause to your broker at tender stage and three useful things happen: we can confirm the required limit is actually available for your trade before you commit to providing it; we can check whether the clause demands the limit per occurrence or in the aggregate, which changes what has to be bought; and we can flag requirements that belong in negotiation, such as indemnities that stretch wider than any insurance will follow.

Arriving after signature with a compliance deadline shrinks all of those options to one: buy whatever fills the number, quickly. It usually works, but it is the most expensive and least considered way to build a programme, and it is entirely avoidable with a phone call made a fortnight earlier.

Frequently asked questions

When does an excess layer start paying?

Only once the limit of the policy beneath it has been exhausted by a covered claim. The excess insurer then pays the part of the loss that falls within its own band, up to its own limit. It does not contribute alongside the primary from the first pound.

Can my excess layer have different terms from my primary policy?

It can, and that is the main danger. A standalone excess wording with an exclusion the primary does not carry means cover for that peril stops at the primary limit. A follow-form layer that adopts the primary terms avoids this, which is why we compare the wordings clause by clause before placing a layer.

Do I need excess layers for employers' liability?

The statutory minimum for employers' liability is 5 million pounds and most insurers issue a higher limit as standard. Some contracts and industries ask for more than your primary insurer provides, and an excess layer is how that additional limit is built.

Is an umbrella policy the same as an excess layer?

The terms are often used interchangeably in the UK, but a true umbrella can sit over several different primary policies at once and may include terms of its own. What matters is not the label but whether the wording follows the policies beneath it or narrows them.

Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority (FRN 724952). This page is general information, not advice on a specific policy.