In November 2018, we published the blog, Best Practices for Phone Exchange 2 International, introducing you to one of our phone validation services and its operations. Here in this blog, we drill down and discuss some of the additional information available in our DOTS Phone Exchange 2 API response through the Note Codes fields. These Note Codes provide deeper insight into the phone numbers you are validating.

Our Phone Exchange 2 service has two operations: GetExchangeInfo, which is able to validate US and Canadian phone numbers, and GetInternationalExchangeInfo, which validates phone numbers from any country. These operations share several Note Codes, which you can see listed in our developer guide, and also have ones specific to each operation.

Below is a list of the additional information that the Phone Exchange 2 service’s Note Codes can provide when validating phone numbers.

NoteCode	NoteDescription	Summary
1	IsUnknownProvider	Indicates that we could not definitively identify the service provider for the phone number. This code mostly shows up in the International operation. It is typically associated with incomplete or bad phone numbers, but does not necessarily mean the phone number is invalid.
2	IsInvalidNumber	This is a big red flag that the phone number is bad. This will show up in the International operation since the GetExchangeInfo operation will return an error for invalid phone numbers.
3	IsPorted	The given phone number has been ported and has switched carriers. We generally consider this to be a good indicator that a phone number is valid. The ported date will show when the number switched carriers.
4	IsLandline	This phone number is registered as a landline phone number.
5	IsWireless	This phone number is registered as a wireless phone number. This is helpful to know for the sake of sending SMS messages
6	IsVOIP	This phone number is registered as VOIP (Voice over Internet Protocol) phone number.
7	IsUnknownLineType	The service was unable to determine the line type associated with the phone number. This code is most likely to show up in the international phone number operation.
8	IsTollFreeNumber	Indicates the provided number is a Toll-Free Access number, such as a 1-800 or 1-888 number.
9	IsGoogleVoiceNumber	The provided number is a registered Google Voice number. There is increased risk for fraud with Google Voice numbers from operators overseas as they can be easily spoofed and changed.
10	IsSkypeNumber	The provided number is a registered Skype number. There is increased risk for fraud with Skype numbers from operators overseas as they can be easily spoofed and changed.
11	IsPortableVOIP	The provided phone number’s registered phone carrier provides local phone number registration without physical address. There is increased risk of fraud with portable VOIP.
12	IsPossiblePortableVOIP	Indicates the registered phone number is likely assigned to a carrier which provides local phone number registration without physical address. There is increased risk of fraud with portable VOIP numbers.
13	IsPrepayPhone	The given phone number is assigned to a phone carrier offering prepay services. There is increased risk of fraud with phone numbers identified as prepay.
14	IsIncompleteNumber	The given phone number was incomplete. Even though a phone provider match was found for the first 6 digits, the number is incomplete and ultimately an invalid phone number. This will primarily show up in the GetExchangeInfo operation. This can be helpful if your database or CRM has separate fields for some other phone number elements (i.e. area code or extension) and then you can look to those fields to see if you can piece a whole number together.

Here are some examples of use cases applying the results of these Note Codes:

• If these phone numbers correspond to incoming orders, and fraudulent orders are a concern, you might flag calls for further review that have positive results for IsGoogleVoiceNumber, IsSkypeNumber, IsPortableVOIP, IsPossiblePortableVOIP, or IsPrepayPhone.
• If you are cleaning a database of contact numbers for future marketing contact, you might flag numbers with positive results for validity codes such as IsUnknownProvider, IsInvalid, or IsIncompleteNumber.
• For TCPA compliance, you have a 15 day grace period to detect if a number has been ported and remove from your calling list. The Note Codes indicate the line type (e.g. landline, wireless, VOIP, etc) if it has been ported and the ported date, helping you remain in compliance.

Porting allows consumers to use their existing phone number when switching between service providers. Numbers can be ported between landline, wireless, and VOIP. Numbers associated with cancelled services can also be reassigned to new customers.

Each application and use can be different and require a specialized approach and application of our Phone Exchange 2 API. Part of getting a Service Objects’ subscription means having access to amazing support and advice from our data validation experts. We are happy to schedule a consultation to help you get the most out of your Service Objects API. Please reach out to us and let us know if we can help!