Getting failed error on my text messages

[Downright]

When I send a text the recipient receives the message but I get a failed to send error. 

[pgn]

This is a long one, but worth checking out, @Kevbev22 - see if any of the advice in here helps - yes I know your msg is delivered, but read on down a ways:

https://www.makeuseof.com/tag/fix-imessage-not-delivered/

[MI5]

@Downright 

This happens often on iPhones because O2 don't support delivery reports so it confuses the system.

To get an accurate response, you need to start all your standard texts with *0# (will not be seen by recipient) and just ignore the iPhone reported status.