To maximize the deliverability rates of your SMS campaigns, and ensure your customer lists are up-to-date and accurate, it's important to validate your customer list. Here are a few recommendations we suggest to help keep your subscriber list formatted properly and validated.

Step 1: Ensure Subscriber Phone Number’s are Correctly Formatted

Long Numbers (VLNs)

Virtual long numbers are the basic and most common types used for sending and receiving both SMS messages and voice calls.

It is strongly recommended to use the E.164 number format. E.164 numbers are internationally standardized to a 15-digit max length.

Phone numbers must start with a country code, followed by a network/area code, and then the subscriber number. Plus prefixes + are not required.

For example: a Croatian number is formatted as 385981234567, while a UK number is formatted as 447712345678.

For more information on phone number formats and best practices, please review the documentation from your OptiText Partner, which can be found here.

Step 2: Scrub List for Duplicate Numbers and Invalid Phone Numbers

Duplicate Numbers

In your SMS campaigns, you should not send a message multiple times to a single number at the same time.

If you set up your SMS campaign to send the same message to the same number twice, when the campaign is launched, the carriers may identify the duplicate messages as Spam.

Invalid Numbers and Format Errors

If your list contains invalid or incorrectly formatted mobile numbers, the system will detect it and will stop messages from being sent to them. This will result in low delivery rates across your SMS campaigns.

There are third-party services offered which enable you to clear and tidy up your number database. It is recommended to use these periodically to boost deliverability and improve campaign results through higher delivery rates.

Step 3: Provide SMS Opt-In/Opt-Out to Optimove

If you already have a pre-existing SMS program, we will need an up-to-date list of your current opted-in and opted-out subscribers to update their consent attributes in Optimove.