How to display your house number
Emergency response teams cannot find you if your house number is not clearly displayed. Believe it or not, a majority are not visible from the street. It's even worse at night. A badly displayed number can cost you precious time in an emergency. 
Union County Address Ordinance click here


The best location
The number should be posted so that it is visible from both directions of travel.
Trees, bushes or other debris should block visibilty from the road.
Numbers should be placed  near the front door within a radius of the porch light and above eye level.
Avoid placing numbers away from the front door such as above garage doors.

Do not use your mailbox as the only means of identification for your house
If your mailbox is not in front of your house or near your driveway, emergency responders cannot locate you if you do not have your house number on your house or on a post or sign in your yard.
Remember to mark your mailbox on both sides.
Numbers on the mailbox door may be great for your mail carrier, but are extremely difficult to see by drivers.

Address signs
Should be placed about two feet from the driveway in the direction of the house.

The best color
Pick a color that has a light and dark contrast with the background. The background is usually the color of the house. This will make the number stand out so it can be viewed from the street. If your house has a dark color, you need a number in a light color. If your house has a light color, get a dark color number. For example, a black number is perfect on a white house. A white number will show clearly on a brick house. A lighted number is even better for easy visibility at night.
If the house color is dark, a number in a dark color will not be visible from street distance. The same is true with all light colors. Use caution with brass or bronze numbers they are difficult to see on many backgrounds.

The number needs a light and dark contrast with the mailbox color. If you go with stickers, the ones with black numbers on white background are excellent. Another option is to mount a sign above or below the mailbox. Don't get a color similar to the mailbox's color. Be sure not to paint over the numbers. Stickers with shiny silver numbers on black background are not visible. 

Sign or post
Reflective signs with a dark background and light letters are easy to see. Avoid using similar colors for the sign and numbers.  

The best size
Bigger is better. The number should be at least four inches tall if displayed on a house or sign . 
Get boldface type. Thick and wide is better
Common mistakes
Can you make out the bronze number? If you were looking around, would it catch your eye? Imagine if you stood further away or at night.

No help. Unfortunately, blank mailboxes like this are everywhere.

On the other hand, black and white stickers are easily noticeable. This is wonderful

A black number on brick is very hard to see from the road. It needs a white number instead

This is what the above looks like with a white number. 

Show only your number. We don't need your name and street. Don't get small numbers and cram all that information on the side of your little mailbox. Only your house number please!