got myself a s4 and at first all was good but now its wont accept txt from son, I can send to him no problem and I can also get calls from him but just no txt ,its now been a couple of weeks and he has went from a s3 to a moto g but still cant get them. any ideas????

Have you checked the spam folder? Left menu key (next to the home key) while in 'messaging', the spam settings are there. His number may have been added by mistake.

that worked, thanx