Error plates are those with manufacturing flaws.  These plates slip through the inspection process and sometimes actually get issued.  In most cases, however, the error is usually caught and the plate is rejected.  If it isn't destroyed, it can be quite a collector's item, depending on the type of error.

The most common errors are:

Inverts

• Partial Invert: When the license plate numbers are stamped out, one of the dies may be put in upside-down resulting in a license plate with one character inverted with respect to the rest.  This is glaringly obvious with most  numbers and letters.  However this may not be at all obvious with the numbers  '9'  '6' and '0', or the letters 'X' and  'I' for example.  Inversion may be slightly apparent with other dies, for example the numbers '8' and '1'.
  
  

You have to look closely, but the first '8' is inverted on these motorcycle plates.  This is a common error.

 
• Full Invert: Sometimes a blank will be inserted upside-down into the die stamping maching resulting in a serial number that is upside-down with respect to the background (or rest of the plate).
  
  

A full invert which is glaringly obvious. Notice the crown covered up by the 'T'. It's amazing it was actually used!

This second motorcycle plate is actually an invert.   Look at the bottom two mounting holes.  They are supposed to be on the bottom (for front fender mounting) but the second one of this pair was stamped upside down. cle plate is actually an invert.

Multiple plates

Care must be taken not to stamp out more than a pair with the same number (or a single if they are being made for a jurisdiction which only uses a rear plate).  Occasionally one forgets to switch the dies, or two blanks are fed into the machine at once by mistake.  Whatever the reason, multiple examples with the same serial number can be found such as a "Three of a kind".



Color errors

If different types of plates are being manufactured on the same day, often different colors may be used for the various types being made.  In these cases a plate may be painted with the wrong colors.  Other common errors are color inversions (reverse of the correct color).  For example, the numbers are painted red on a white background, instead of white on red.

Sometimes a plate is fed upside down into the roller painting machine.  The result is that paint applied to the back of the plate instead of the front, making it look debossed instead of embossed or the lettering backwards.
 

This 1987 Ontario plate looks ordinary, until you turn it over.


Occasionally a plate will be stamped but never fed through the paint rollers.  This results in a plate without the numbers painted.

Others
 

• Crooked letters (not properly aligned in the stamping machine).
• Fingerprints caused by handling the plates before the paint is dry.
• Misplaced dividers, such a a dot in the wrong spot.
• A missing feature on the plate, if the die used to stamp out that feature (such as the Crown on Ontario plates) was not inserted into the stamping machine.

A defect in the white paint on some of the 1955 Ontario plates, caused it to run into the dark blue background.  The result is a pinkish hue.

The same happened with these 1973 Ontario motorcycle plates.  Notice how the numbers in the second plate take on a bluish hue.

John Hayes / Dave Steckley: 7-digit Ontario invert

Rest are attributed to the webmaster.

(Wouldn't it be nice to show other provinces besides Ontario?)