Why are telephone numbers changing? How long will the customers be told about new number on the phone?

Recently the local phone and fax numbers in this city are going to be changed to 8 numbers. How can we ensure smoother transition. The following is an interview with official from local telephone company, Collins Spencer. She is going to give us some detailed explanations about it.
      Ms Spence, can you tell us why, how and when are the numbers changed?
       Well, in recent years there has been dramatic growth in the local phone system, especially in parts of the city where all kinds of business are thriving.  So along with the demand for additional phone services, mobile phones, fax machines and pagers, as well as new phone companies we are actually running out of numbers.
     Over the next 5 years, starting July this year, every phone number in the city will eventually gain an extra 1 or 2 digits, so we will all have 8 digit numbers and a 2-digit area code. And the city will have a much larger supply of numbers for future growth and innovations in phoning services.
     Some people wonder how their customers will be informed what their new numbers are.
     This may not be as complicated as some people think. Beginning in May this year there will be an extensive nation-wide advertising campaign to make everyone aware of the number change. There will also be regular updates on the national and local press. And a complete timetable for every phone region in the city will be included in all White Pages directories from July this year.
     But more importantly, you will have time to let all your customers and suppliers, both locally and overseas, know in advance that your number is changing. Then for at least 6 months, after the changeover, anyone accidentally calling your old number from anywhere in the country will be automatically connected to the new number at no extra charge. Then for a further 3 months, anyone who dials your old number will receive a recorded message advising them the change of your number.
     But how will people overseas call me?
     Our local telephone company will advise other countries about the change. So overseas callers will be able to find out your new number from their local operator. Also, like phoning from within the country, during the first 6 months after changeover, overseas callers who accidentally call your old number will be automatically connected to your new number at no additional cost. Then for the next 3 months, a recorded message will advise any overseas callers of your new number.
     That will be very convenient. Then Ms Spencer, many people want to know what they need to do about the change?
     Well, before your number changes, you should plan to update your stationery, promotional material, signs and any material where your number appears. With 12 months written notice before the changeover, you can minimize the costs by planning ahead. As the changes occur you will also need to update programmed numbers in computers, fax machines and phones and modify barring facilities on phones and fax machines. Database phone lists and documents will also need to be updated.
     Then I have a last question. Will the cost of calls change?
     Oh, no. Don’t worry about that. The change of the phone number will have no effect on the cost of making a call, no matter if it’s a local or long-distance call. National long distance calls will still be charged according to the distance and time, just like they are now.