What is the right format?
In order to properly process a message our system needs to know which country you are sending to. You can do this by adding "00XX" or "+XX" to a mobile phone number, where XX is the country code.
Correct format examples
WRONG format examples
How to change it into the right format
Via the Address Book app Only recommended when you're sending to 1 country
If you're uploading an file into the Address Book app, you will be asked to select a destination for numbers with missing country codes. Select the correct destination country and continue your upload.
You can change the format of "612345678" from wrong to correct with 1 simple formula.
Where XX = Country Code & NUMBERCELL = the recipient's phonenumber
Then move your cursor towards the bottom right of the formula's cell until a +-icon appears. Double click to execute this formula for every cell until the next empty cell.