I'm an overseas filer. The TurboTax Home Business 2017 app does not accept my international phone number in the "Personal Info" section even I've selected "foreign address" from dropdown menu. My phone number apparently doesn't follow the app's validation rules, which seem to be set up for the continental U.S.
When a filer doesn't reside in the U.S., their phone number will likely have a different format and be longer than that of U.S. residents, and the app should be set up for this.
Just leave the phone number field blank and press on. Not even a space. The IRS will never call you on the phone anyway. Even if you are in the U.S. To this day I don't understand and can't comprehend why the IRS has a space on the form for your phone number. They will never call you. The IRS always deals with tax issues with a tax filer by mail so that they have it in hard copy writing should the need arise to prove anything in a federal court.