What to do before the system comes into effect
It is advisable to review the established validation strategy. The main factors to consider in this task are the following: the possible additional cost vs. additional territorial scope (depending on the number of countries), simplified internal and external administrative process of a unitary patent compared to registering several national patents, and the loss of flexibility because a unitary patent will be maintained or lapsed in its entirety (the single renewal fee will prevent the dropping of countries over time).
Applicants would be wise to evaluate the patent portfolio to decide which patents and/or patent applications should be opted-out of the system to avoid the competence of the UPC.
Prior to the unitary patent system is in force, if the grant of a patent application which is a unitary patent candidate looks likely to occur, applicants might want to consider using the transitional measures provided by the EPO (to file early requests for unitary effect for those patents eligible, as well as to file a request for a delay in issuing the decision to grant a European patent after dispatch of a communication under rule 71(3) EPC and before approving the text intended for granting for those patents that would be granted before the start of the new system).
In new license agreements, applicants have to bear in mind to try to stipulate who has the right to make or to impose a decision on whether or not to opt-out, and who has the right to enforce a patent. A review of already existing license agreements (both patentee and licensee) to try to stipulate the previous issues is recommended as well.