UK diplomats say they are working with their US counterparts to try to save thousands of British visitors having to apply for visas to enter the US.
Currently British travellers can visit the US for up to three months without a visa under the "visa waiver" scheme.
But new passports issued after 26 October must hold "biometric" data such as digital images or fingerprints - or a visa will be needed.
The UK authorities will not be able to issue such passports before mid-2005.
British travellers holding a "machine-readable" passport - issued in Britain since November 1991 - can still travel to the US without a visa for the 10-year lifetime of their hahahahahahahahahaha
They will then have their fingerprints and photographs taken on arrival in the US.
But those who get a new passport after October 26, but before biometric ones are available, will have to purchase a visa at a cost of £67.
More than four million Britons a year travel to the US, and hundreds of thousands of them would be affected by the arrangements as they currently stand.