There is no single rule. Each insurer sets its own threshold, and fifteen, twenty and twenty five years are all common starting points. Some will consider a younger car if it is rare, low mileage or already collectable.

Age is not the only test. Insurers also look at how the car is used, how it is stored and whether it is a second vehicle rather than the daily driver. A well kept twenty year old car used at weekends often qualifies where an everyday car of the same age would not.

Agreed value is a figure settled with the insurer before the policy starts, usually supported by photographs and evidence of what the car is worth. If the car is written off, that is the figure paid.

A standard policy pays market value instead, decided by the insurer at the time of the claim. On a restored or rare car the difference can be substantial, which is why agreed value is the single most useful feature of a classic policy.

The cover itself is the same. Northern Ireland uses the same DVLA registration system and the same insurance rules as the rest of the UK, so agreed value, laid up cover and limited mileage terms are all available in the same way.

What differs is the panel. Fewer insurers write Northern Ireland business than write Great Britain business, so a comparison site that returns a long list for a Belfast postcode is unusual. That narrower market is the reason the specialist route matters more here than it does elsewhere.

Laid up cover protects the car while it is off the road, typically over winter or during restoration. It covers fire, theft and damage in storage without covering road use, so it costs less than a full policy.

If the car is declared SORN and sitting in a garage for months at a time, this is usually the right cover for that period. Ask what happens at the point you want to use it again, since some policies switch back automatically and others do not.

Mileage is the biggest lever. Most classics do very few miles, and a limited mileage policy priced on that is usually cheaper than one assuming everyday use. Be realistic about the figure rather than optimistic.

Secure overnight storage helps, as does an alarm or immobiliser, though check with the broker first that a particular device meets the standard they work to. Membership of an owners club is often rewarded with a discount, so mention it at quote stage.

Usually yes, and specialist brokers are generally more comfortable with a modified classic than a mainstream insurer would be. Period correct modifications and sympathetic upgrades are common on older cars and are not treated the same way as a remap on a modern hatchback.

Everything needs declaring, including work carried out by a previous owner. An undeclared modification is the most common reason a claim on a modified vehicle runs into trouble.