Standard UK comparison-site policies are almost always inadequate for modified cars — they exclude performance modifications, impose usage restrictions, and pay market value (not build value) at total loss. This guide covers everything you need to get the right UK cover for your modified car.

What Must You Declare to UK Insurers?

Under the Consumer Insurance (Disclosure and Representations) Act 2012, you must take “reasonable care” not to misrepresent your car to an insurer. This replaced the old blanket disclosure duty — in practice, it means answering the insurer’s questions accurately and declaring every modification that differs from the manufacturer’s standard specification, since a “qualifying misrepresentation” can let the insurer avoid the claim or the whole policy.

Required declarations include:

• Engine modifications (exhausts, intakes, camshafts, forced induction)
• Suspension changes (lowering springs, coilovers, anti-roll bars)
• Wheel and tyre upgrades (size, brand, type)
• Bodywork changes (spoilers, splitters, vinyl wraps, paint)
• Interior changes (roll cage, racing seats, harnesses, stripped trim)
• Electronics (ECU tunes, standalone management systems)

Best UK Specialist Insurers for Modified Cars

The following specialists are recognised in the UK market for modified car cover:

• Adrian Flux — one of the UK’s largest specialist brokers; covers most modifications
• Footman James — strong on classic and competition cars; their FJ+ product offers agreed value, track day cover, and legal protection add-ons
• Performance Direct — focused specifically on performance and modified vehicles
• AIB Insurance — competitive on track-use endorsements
• Brentacre — good for heavily modified or kit cars

What Actually Drives the Cost

UK specialist insurers quote modified car cover individually — there’s no published rate card, and premiums vary enormously by insurer for the same car. What consistently moves the number:

• No-claims bonus (NCB) — remains your single biggest discount factor, even with significant modifications
• Extent of modifications — a mildly lowered car with an exhaust is rated very differently from a heavily built, forced-induction engine
• Age and location — the same underwriting factors that affect any UK policy still apply on top of the modification loading
• Agreed value — the higher the payout on a total loss, the higher the premium
• Track-use endorsement — priced individually as an add-on where offered

Get quotes from at least two or three of the specialists above rather than budgeting off a number you’ve seen online — the spread between insurers for an identical build can be substantial.

Track Use in the UK

UK modified car policies typically exclude all “competitive use,” and most exclude any track use by default. You can add a track day endorsement to specialist policies for an additional premium, priced individually rather than off a fixed rate. This covers non-competitive circuit days only — for sanctioned motorsport (sprint events, hillclimbs, and similar), you need a dedicated motorsport policy, typically arranged through your club or a specialist motorsport broker recognised by Motorsport UK (the governing body formerly known as the MSA, rebranded in 2018) or the BRSCC.

Sources

• Consumer Insurance (Disclosure and Representations) Act 2012
• BRSCC — MSA Rebrands as Motorsport UK
• Footman James
• Adrian Flux