I received a new SIM last Friday, put it into my phone, texted PORT to 07507307996 as instructed in the welcome email (which said the text would be free). I then replied to the three texts that followed, confirming that I wanted to port my number, the number I wanted to port, and the PAC.
I'll skip over the disappointment that the number hasn't ported yet, despite claims that it would take one business day (elsewhere it says 1-2 business days - some consistency would help).
The port-in process takes up to 1 working day when processed before 6pm on a weekday or up to 2 working days when processed after 6pm to complete; there will be some disruption on the network in the meantime and we don't process ports of a weekend, but this is part of the process. You can use your existing SIM until the transfer is complete and you will know this as your current SIM will stop working. When this happens, pop in your Plusnet mobile SIM and you'll be good to go!
With regards to the mobile number that has been sent. In the past, it has been found that depending on the handset, activation texts for services such as iMessages or certain applications have automatically been sent. I would advise to check the apps on your handset for any verification set up process that could have requested this.
I'm sorry for any confusion caused with the 'Text To Port' process, this will be deducted from your allowances however, if you exceeded your allowance, these numbers would be free and can still be sent.