SMS Tips & Tricks

Invalid or Incorrectly Formatted Mobile Number in the Campaign

If you add an invalid or incorrectly formatted mobile number in a campaign the Infobip platform will detect it and won't send the message to such number, so you won't be charged for it.

There is an additional service offered by Infobip which enables you to clear and fix your numbers database called HLR service. It's recommended to use it periodically to improve the numbers you own and improve campaign results through higher delivery rates.

Duplicate Message – the Same Number Twice in the Same Campaign

If you try to send the same message to the same number twice in the same campaign the Infobip platform will detect it after launching the campaign and won't send twice.

Number Format Used in Campaigns

We strongly recommend using the E.164 number formatting. E.164 numbers are internationally standardized to a fifteen-digit maximum length.

Phone numbers must start with a country code, following by network code and the subscriber number. The "+" prefix is not needed. Phone numbers that are not E.164 formatted may work, depending on the handset or network.

For example, a Croatian number should look like 385981234567, while a UK number should look like 447712345678.

Message Delivery to Roaming Numbers

When launching a campaign there is a possibility that the recipient will be in roaming. All efforts will be made and the platform will forward these messages further to reach the recipient, however, the delivery in such situations can't be guaranteed.

Scheduling Messages

To schedule messages to be sent in advance you can use our API or the Infobip Portal.

Infobip Portal offers the option of scheduling when the messages should be delivered. The user can specify the start and the end time along with the desired time zone. The picture below shows exactly how the scheduling menu looks like in the web interface.

Scheduling through HTTP API requires Client to set sentAt to the desired value. This is how the format should look like: 2015-07-07T17:00:00.000+01:00.

Scheduling over the SMPP API requires setting schedule_delivery_time to the desired value by entering it in the relative time format. For an example, “070605040302100R”. This means that the message will be delivered in 7 years, 6 months, 5 days, 4 hours, 3 minutes, 2 seconds and 1 tenth of second from now.

Sender Name

Sender name or sender ID is the word or number that is shown on end-users devices as a sender of an SMS message.

Sender name types





  • Recognizable sender ID constructed from any combination of numeric and alpha characters (0-9, a-z, A-Z)
  • A sure way to distinguish if the sender is considered alphanumeric is the inclusion of non-numeric characters



  • Numeric Sender ID (aka Long Number) is a typical mobile number in standard numeric form (0-9)
  • Using so-called VLNs - Virtual Long Numbers (leased from MNOs or through messaging companies) will enable the end-user to reply back and for you to collect their answers (two-way communication)
    If used internationally, network sending the SMS must be within operator roaming reach for a reply to be received


Short Code

  • Memorable 4 to 6 digits number, basically shorter version of numeric sender IDs
  • Leased from MNOs or through messaging companies and typically used for SMS sweepstakes, polling, TV voting, etc (two-way communication)
  • Depending on the country they can also be used for strict one-way campaigns as a regular sender ID


Restrictions in Length

A general rule for the allowed length of sender name is:

  •  3-11 characters maximum length for Alphanumeric senders
  •  3-15 digits maximum length for Numeric senders
  •  4-6 digits for Short Codes

However, each country or network may have its own length restrictions.

Registration Process

Depending on rules and regulations (country or network level) sender IDs might require registration prior to submitting traffic. The registration procedure is usually unique to each operator requesting it, varying from a simple pre-approval to sender descriptions, text templates and additional documentation for each sender to facilitate requests. Waiting time for the registration to be processed is usually proportionate to registration complexity and highly operator-dependent.

Before sending any type of traffic towards a new country/network we advise contacting your account manager for more information regarding possible sender restrictions.

Sender Name Information for specific countries

On the below link you will be able to find sender information (and more) for specific countries. In case you need information about sender regulations for countries that aren’t listed, please contact your dedicated account manager.

Long SMS

All SMS messages are charged per message. Long SMS messages are basically broken in several SMS messages and reassembled when they reach mobile phone. They are charged based on the number of parts where each part is one SMS message.

The maximum size of a long message varies between mobile networks. We suggest constraining to sending no more than 5-7 long SMS parts. Your account manager will provide more details for a specific network.