With all the uncertainty over BREXIT is is definitely worth reviewing your GDPR to ensure you have all the appropriate documentation in place. Where you transfer data to/from a third party and especially if you transfer outside the EU, you must have specific contract terms in place. For more info, take a look at this information from the ICO.
Our optindigo document pack includes a useful template and we will pre-fill for you.
Hope this helps.
Good luck all.