SMS Deliverability

SMS deliverability

General deliverability issue

There are a few factors that can affect the deliverability of sms. If you are experiencing a problem that is consistent over several markets you can look at:

  • Number formatting - Mobile numbers must start with 00[country code] or +[country code], e.g. 0046 or +46 (where 46 is country code for Sweden).
  • Opt out - many operators bann messages that don't have the ability to opt out.
  • Alphanumeric Sender - Make sure you control what is legit in the receiving market in terms of sender. Some markets don't allow alphanumeric sender names such as "Customer X" but need a number instead.

Market specific deliverability issue

If you are experiencing deliverability issues to a specific market there are a few factors that can be looked at.

One could be that the route into a specific country is being blocked by operators for some reason. This is something we, at Symplify, monitor and if this occurs a new route will be taken into that specific country for the next send out.

There are also a few markets that have stricter regulations of what can be sent in an SMS. These markets are among others New Zealand, Thailand and NAM (North America +1). The operators in these countries will block traffic depending on the content of the sms.

If you are experiencing deliverability issues, the reason could be that your content includes something that triggers the filters on the operator side. 

  • Words like bonus or offer can be lowering the deliverability into some countries (please note that words that might affect the deliverability are changed and updated constantly). 
  • The sender name can also be blocked on the operator side - try using another sender name.
  • Links and short links can also be reasons for a low deliverability.
  • Some countries require sender authentication (reach out to your account manager who can guide you).
  • Make sure you always include the option to opt out from your communication.
  • Communicate within reasonable hours of the day, some filters only accept sendouts during daytime.

The Canadian market is one of the more strictly regulated markets and has one other exception: they only support SMS with a maximum of 140 characters and normally this is 160 characters.


It is really important that you keep updated on the market's regulations to ensure you communicate in a way that will be within the regulations and accepted by the operators.


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