What the law says
Most of the time, whether or not you choose to carry spare bulbs is up to you. But, in some countries, it's a legal requirement. Both France and Spain require 
drivers to keep spare headlight bulbs in case of an emergency.
While it's not likely that a police officer will pull you over and ask to see your spare bulbs, you may find yourself in trouble if a bulb burns out and you're not ready with a spare. Failure to be prepared with spare bulbs could lead to a ticket and a modest fine.
Advantages of carrying spare bulbs
Even if it's not required by law, there are plenty of good reasons to have spare bulbs on hand. For one, it is a legal requirement to have two working headlights. If one bulb burns out and you don't have a spare, you could wind up with a ticket or a fine.
Having spare bulbs in your vehicle is also a good safety measure. Think about how important your headlights are when driving at night. Without them, you can't see the road ahead and other vehicles can't see you. You would never purposely drive around with a burnt-out headlight bulb. So, why not be prepared with a back-up, just in case?
Installing spare bulbs
One reason drivers neglect to carry spares is that they don't know how to install their own bulbs. Many drivers take their car into the shop and have a 
mechanic install new bulbs when theirs burn out, but this isn't always necessary. Anyone can learn to change a headlight bulb, and can be a simple task once you get to grips with it.
Changing a headlight bulb on the side of the road at night isn't always the best idea, however. If you're on a short trip, especially in a well-lit area or during the day, it may be safer to wait until you get home to change your bulbs.
If you have trouble figuring out how to change your headlight bulb, consult your vehicle owner's manual. There should be instructions on how to locate and replace your headlight bulbs.
Other spare bulbs
It makes sense to carry spare headlight bulbs at all times, but what about the other bulbs on your car? Should you have spare tail light, sidelight, or interior bulbs in your vehicle?
In most cases, this isn't necessary. Driving without headlights at night is extremely dangerous. When a headlight bulb goes out, it's best to replace it as soon as possible. Other lights are less important. If a tail light burns out, for example, you can usually safely wait until you're home to replace it.
If you'd rather be on the safe side and keep a few spares to hand, check out the NEOLUX Spare Bulb Kit. It contains a variety of popular fittings including H4, H7, W5W and P21W, along with a choice of fuses.
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