Know your rights
The shop can recover all its direct losses for damaged stock if you didn’t take reasonable care or adequately supervise your children.
The amount is usually the retail price of the product including any loss of profit from the shop now being unable to sell it. You may also have to pay for any damage to shop fittings caused by your actions.
You are not liable to pay if an event outside your control leads or contributes to the damage.
Your liability is limited if any shop stock breakages are caused by other factors, such as placing fragile items on unstable shelves.
Although the shop could choose to claim on their insurance, this will depend on whether it is worthwhile for them to do so. Even then, their insurer may claim from you what they had to pay out to the shop.
Your house and contents insurance may cover the cost of any damage as well, although you will have to pay your excess.
A sign like ‘If you break it, you buy it’ may have no legal effect. Whether you have to pay the shop for a breakage will depend on whether you failed to take due care.
But, a shop can display a sign warning you to take care around goods that they know are fragile and need careful handling. For example, ‘Please ask a sales assistant if you would like to look at these products’.