I have seen several threads discussing dialing extensions with an iPhone. It is fact that you have to insert a pause ( between the phone number and extension. This of course goes against the usage of x or ext. which has been integrated into the corporate environment over the years. This where the problem lies, where those that are transitioning to the iPhone are having difficulty with the extension dialing with the iPhone. Reason is that many have an extreme number of contacts, many of which have extensions programmed in already and it is a real pain in the rear to go back and modify all those contacts to conform to the iPhone. I have found a way to make it as seemless and painless as possible, here is what I found: Case: 3,000 contacts stored in Outlook 2010, ~50% have extensions (1500). Need to convert them to the iPhone to dial the company number and pause for user intervention and dial the extension number. Problems: Modifying 1500 contacts is too time consuming Without modification the phone won't even dial the number as it states "Invalid Code has been entered, rendering 1500 contacts useless. Here are the steps that I used to accomplish my goal: Create a backup of my Outlook Contact Database Export my database to Microsoft Excel (Click on "Contacts", then File|Options -- Advanced|Export) This loads the Import and Export Wizard. Select "Export to a file"-Next> Select "Microsoft Excel 97-2003"-Next> Select the folder "Contacts" (should already be highlighted)-Next> Select a destination file folder and name. Verify the Fields are approriate. (You should export every field possible IMO.) Click "Finish". Open the newly created Excel file. Locate the coulmns with phone numbers with extensions (i.e. Business Phone, Assistant Phone, Company Phone, etc.) and click on thecoulmn header of all the rows (Hint: Hold down the CTRL button to select mulitple columns) Once all the respective columns are highlighted, press CTRL-F to open the Find/Replace dialogue. Select the "Replace" tab. In the "Find what:" box enter "ext." (without the " marks) In the "Replace with" box: enter "; " (there is a space after the ";"; I'm not sure if this is necessary as I didn't do it the other way but just in case.) Click "Replace All" It now will replace all instances of "ext." with "; " Repeat steps 12-14 with ext, x, etc. (I do it in this order because if I did x first it would end up with entries like this: e; t. or e; t, when it replaced the "x" in "ext." with "; " Verify all modifications have been made and are correct. Save the Excel file. Make sure you have a backup for the next step. I clear my "Deleted Items" folder and then delete all my contacts in Outlook, which moves them to the "Deleted Items" folder. Once the Contact folder is emptied, I then Import my contacts in the same fashion as Step 2 only this time instead of "Export to a file", I select "Import from another program or file"-Next> Select "Microsoft Excel 97-2003"-Next> Browse for the modified Excel file. Make sure the "Contact" folder is highlighted.-Next> Make sure all the fields are selected in Map Custom fields and they are directed to the appropriate destination in Outlook. Click "Finish". Upon Completion of import, open Outlook Contacts and verify the modifications. Resync with iTunes. It's your choice as to whether you delete all the contacts from the phone first or whether you simply tell iTunes to overwrite any data on the iPhone with the import data. (I prefer deleting the data first to avoid any duplication.) Finally, open up the contacts on iPhone and verify. Younow should be able to dial a contact with an extension and the iPhone will display "Dial 123" at the bottom right hand corner and will dial the phone numberand wait for user intervention. I hope that this helps. I would consult with your IT department and backup your data before taking on any type of database modification and I do not take responsibility for the results of this process, simply sharing what I did that worked for me and I hope it works as well for you as it did for me. This project took about 30-60 minutes to complete.