But, again, if you're not compliant they'll just write a letter telling you this and asking you to come into compliance.
At that point you can check your understanding of the law and what you're doing and write back letting them know why you think you're in compliance; or you can change your process; or you can take it to court.
What happens when that is not possible though? E.g. in the case there is a breach and it is found out because of it that you were not compliant. Do they still write you a letter? Also , is this procedure common for all DPAs or just for the UK?