Starting March 21, businesses who want to get deep discounts for delivering presorted mail to post offices will have to place bar codes with 11-digit ZIP codes, rather than nine-digit ZIP codes, on all their mailings.
Bill Reynolds, Lawrence's postmaster, said firms now using the nine-digit bar codes should have no trouble adding two more bar codes.
"It's not as difficult as it sounds," Reynolds said.
He said the nine-digit code has allowed mail to be sorted to the even or odd address numbers on the side of a street. Going to 11 digits will allow mail to be sorted down to the delivery point on a letter carrier's route, he said.
Reynolds said 85 percent of the current mail volume is from business. He said he was aware of no effort to get the rest of the public to move to an 11-digit Zip Code.
The postal service has never required that mail have a Zip Code, although it is used on 98 percent of all mail, he said.