How to stop SMS spam?

What NOT to do
Reply with a SMS saying STOP, like they ask you to. Not only that has little chances of working, but it's also confirming to the spammers that you are human.

What to do
Smartphones have Anti SMS Spam apps. I've never tried them, so I cannot recommend one in particular. But from whatever little I understand of the underlying technology, the more people are using it, the more accurate it is.

PS: Beware of false negatives. Choose an app that lets you retrieve filtered SMS easily.

What I do is, I search for the name of the company the SMS is from, and then just ask them to unsubscribe.

AvoK95 wroteWhat I do is, I search for the name of the company the SMS is from, and then just ask them to unsubscribe.

That was fairly simple. I did not know that could work.

In HTC Sense you can block any phone number or even sms advertising name so not only it will give a busy tone when they call you but they can't send you SMS :)

How do you do that on an iPhone without jailbreaking it....

In iOS 7, try the following (I haven't tested it)

1. In the Messages app, select a message from the company you want to block.
2. Tap on Contact, then Info.
3. tap "Block this Caller".

If you're on an older iOS and it is not jailbroken, you are out of options.

rolf wroteHow do you do that on an iPhone without jailbreaking it....

samer wroteIn iOS 7, try the following (I haven't tested it)

1. In the Messages app, select a message from the company you want to block.
2. Tap on Contact, then Info.
3. tap "Block this Caller".

If you're on an older iOS and it is not jailbroken, you are out of options.

rolf wroteHow do you do that on an iPhone without jailbreaking it....

@Samer, i always use it, it works :)

Wow, OK thanks, glad to see Apple have implemented SMS blocking in 2013...
Anyway, I didn't want to upgrade to iOS 7. I'm happy with 6, I like the "classic" look, not very impressed with the new interface, and not very keen on filling up the little free space that I have left on my device, nor increasing the workload on it's CPU, but I might do it, after all.

Thanks for the tip.