he U.S. Customs Service has begun a final push to get shippers to sign up for its Automated Export System. Good business sense - in fact, just plain, ordinary common sense - dictates that most should comply.

The question is whether their required export documentation is going to be filed with and processed by the federal government quickly and productively on computer, or sluggishly and expensively on paper.Many already use an aging electronic system to file their Shipper's Export Declarations. But that system, the Automated Export Reporting Program, is not Y2K-compliant and will cease operations on New Year's Day. Then everyone must either use AES, or file on paper.

And even though the clock is ticking ever more loudly toward that date, there's a closer deadline. Shippers who want to electronically file export documentation up to 10 days after a shipment has left the country - flexibility that is important to many - must win approval in advance. The process takes about 30 days. That means Nov. 30 is the last possible cutoff for anyone who wants that ability, known in AES jargon as Option 4, when the old automated program ceases to exist.

Anyone who isn't cleared for Option 4 by Jan. 1 is going to lose a great deal of flexibility.

And anyone who hasn't signed on to AES itself and installed the necessary computer softward is going to face a logjam of pre-departure paperwork - and cargo delays that could be lengthy, difficult and costly.

A lot of businesses are running that risk. By the end of October, AES had 276 exporters and freight forwarders on its rolls. Another 185 exporters who now use the old automated program had not signed on to the new one. And 250 more currently file their SEDs on paper.

AES offers something for everyone. Its basic goal is to move as far away from paper as possible, reducing the expense and improving the efficiency of filing and processing export documentation. Customs says that could save up to half the $100 million exporters now spend annually to file some 500,000 paper forms every month.

At the same time, the system will provide the government with timely and accurate statistical information - it's estimated that up to 7 percent of U.S. exports now go unreported, distorting trade-balance calculations alone by up to $44 billion a year - and improve enforcement of export laws.

What's unusual about AES is that it was designed with a great deal of industry participation. The government high-handedly introduced the original version without options in 1995. Virtually no one enrolled. The Census Bureau, which gets the information, and Customs, which collects it, ultimately sat down with shippers, forwarders and carriers and hashed out a program that could work for all. That included four filing options that depend on license requirements and shipper choice.

Reports from companies already participating are positive. Reports from companies that don't are going to be highly negative come Jan. 1.

So if you get a call from Customs advising you to sign up with AES, take the advice or contact a forwarder that has. And act quickly.