A plus (+) sign at the start of a telephone number indicates that it is an international number. When the number is dialed, the + sign is replaced by a specified international prefix if the number is an international number, or is ignored if the number is a national number. For example, the prefix for international calls in the UK is 00, so to call the US number +1 503 123 4567 you dial 00 1 503 123 4567. To call the same number from the US, you dial only 503 123 4567.

The way in which your autodialer interprets the + sign depends on which version of the dialer software it is running. To find this out, look at the first line of your dialer's setup program.

The definition of “international” and “national” depends on the location of the dialer you use.

The dialer interprets the + sign as previously described. This means that all numbers in sample files can be entered using the + syntax and the dialer will work out whether or not to dial them as international numbers.

The effect of the + sign depends on the phone network to which the dialer is connected. To start with, UNICOM Intelligence Interviewer replaces the + sign with value of the InternationalAccessCode property. If the number is an international number with respect to the location of the dialer, it is dialed as such. If the number is a national number relative to the dialer, the behavior depends on the phone network. Generally, international phone numbers can be specified using the + prefix, but national phone numbers must be specified as national phone numbers.