Businesses are being reminded that the telephone dialing codes for six areas of the United Kingdom will change during the Easter weekend and that they should alter any preprogrammed equipment, such as call logging systems, fax machines or ISDN connections, before the change-over date on April 22. The areas with new codes are London, Cardiff, Coventry, Portsmouth, Southampton and Northern Ireland. Details are available on 0808 224 2000 or www.numberchange.org.