GDPR comes into effect on May 25th 2018. We have been in contact with the Data Commissioner Office to clarify the regulations around SMS Marketing. Sendmode will ensure your Bulk Text and SMS Marketing is compliant.
What do I need to do with my current marketing lists?
Your current lists are valid. See responses from Data Commissioner here.
If you have received consent and have marketed to your customers in the past 12 months, giving customers the option to opt-out, there is no requirement to ask them to opt in again.