Does iCloud back up text messages all the time?



I have come across a statement from pcadviser, which is best-read technology magazine and website in the UK that iCloud doesn’t back up SMS in all territories, and for all phone operators. And the editor’s UK O2-operated iPhone 5 falls into this category, meaning his iPhone 5 cannot back up his messages to iCloud. I have checked the support community and there is no evident statement that when iCloud does not back up messages and why.
Actually, if you go to the support page for iCloud, you will find that iMessage, text (SMS), and MMS messages are included as what can be backed up to iCloud.
I have followed the steps offered by the editor of pcadvisor to check whether the messages have been backed up to iCloud by logging in to with your Apple ID and password only to find there is no icon for messages which proves that my messages on my iPhone haven’t been backed up. But I am not sure what the reason is.
Then I try a piece of third party software, iFonebox, to make sure whether the iCloud backup file contains the messages. Fortunately, I have got all my messages extracted to my computer. I still have no idea at all why the option for message does not show after I sign into iCloud with my Apple ID, let alone verifying whether it is true that iCloud does not backup messages for certain territories and carriers.
One thing I am definitely sure is that backing up with iCloud is neither perfect nor 100% safe.
For one thing, iCloud offers only 5GB free storage space, if you have bulky data on your iPhone and want to backup to iCloud, there would be insufficient storage space. You need to either upgrade your storage plan which is not free any more or reduce some data to make more room available.
For another, you cannot backup certain data like messages selectively , nor can you restore certain data from iCloud backup file. To recover lost messages, for example, you have to restore your iPhone with the entire iCloud backup file. And you need to erase all the content from your and setting up your iPhone as a new one before starting restoring from iCloud backup.
What is worst, if the iCloud backup is unfortunately corrupted, there is no way at all to restore, as iCloud does not allow restore or transfer part of the backup file.
So, at last, I strongly advise to download some third party software, like iFonebox which is professional iOS data recovery software and is able to recover certain data including Contacts, Notes, Messages, Photos, Voice Memos, Bookmarks, Reminders and Calendars etc from iPhone, iPad and iPod Touch as well as iTunes/iCloud backup file. With this kind of application, you can extract and transfer data which is important and bulky to computer for record-keeping or backup.
Do remember to have a safe backup for your data on your iPhone, iPad and iPod Touch, because everything that is not saved will be lost.