Federal law taking effect on January 1, 1957 mandated a nationwide standard size license plate of six inches by twelve inches.  For Connecticut it meant terminating the distinctive 9 1/4-inch by 6-inch markers that had been used since 1932.  In conforming to the new regulations Connecticut began issuing a newly designed aluminum marker painted in the state colors of white characters on a blue background.  The marker also had a white raised border and a blue back.

For the first time since Connecticut began supplying markers in 1905 the state name was completely spelled out on the bottom of the plate.  The tab box was eliminated though the use of tabs containing expiration dates continued.  To the right of the word “CONNECTICUT” were three slots for placement of the yearly validation tab.  The tabs themselves for 1957 and 1958 were now made of thin aluminum with embossed letters for the last two digits of the year and a serial number stamped in an extension on the bottom.  The 1959 and 1960 tabs had only the last two digits of the year embossed on them.

All 1956 passenger registrations being renewed for 1957 that had letter-over-letter prefixes were issued markers in a new format wherein the prefix was placed horizontally rather than vertically.  Those 1956 markers being renewed for 1957 with letter-over-number or number-over-letter prefixes were assigned new horizontally lettered prefix plates that started with “BC” and continued to “BI” followed by four digits.  Beginning in early 1958 the DMV began issuing six digit only markers starting at 100,001 with a dot between the third and fourth numbers.  This series continued into 1965 until reaching 999.999.

Passenger registrations changed in 1961 from a standard expiration on December 31 of each year to a staggered system that took effect in with the earliest expiration carrying a March 1962 date.  There were no 1961 expiration tabs used for passenger markers that year.  The use of aluminum for the tabs continued with the month of expiration and the last two digits of the year embossed.  The last metal tabs to denote the expiration of a passenger registration were February 1963.  Starting with expirations in March 1963 the metal tab system was replaced with stickers displaying the month and full year of expiration.  The practice of stickers to denote the month and year of expiration continues to the present time.