What is freedom to operate, and how does prior use affect it?

Can we keep using technology we already developed?

Suppose your business has used a confidential mixing method for several years. You then discover that another company holds a patent that appears to cover it. Your immediate question is whether you can continue production. That is a freedom-to-operate question: does someone else’s patent restrict what your business wants to do?

Your earlier use matters because it may support a right to continue despite that patent. To assess this, a patent adviser needs to establish both whether the patent covers your method and whether your earlier activity meets the local conditions for prior-use protection.

For the practical steps to document earlier use, see what evidence to preserve for prior-use rights. Here, the question is how those records help establish whether your business can continue operating despite a particular patent.

First check whether the patent covers your operation

Give the adviser the technical description of the method you use, the countries where production and sales take place, and the patent you have identified. The review compares your method with the patent’s claims—the numbered statements defining its protection—and checks whether the patent is in force in the relevant countries. A similar title or drawing does not establish that your activity falls within its scope.

The Swiss Federal Institute of Intellectual Property describes this focus on claims, scope and legal status. If the patent does not cover your activity, or is not in force where it matters, you may not need a prior-use defence against it. A wider FTO review also considers other potentially relevant patents and published applications.

Establish what your earlier use allows you to continue

If the patent presents an obstacle, the next question is whether your business qualifies for prior-use protection. The relevant dates, territory, activities and person entitled to rely on the right depend on national law. Some systems recognise certain preparations as well as actual use; others apply different conditions. WIPO’s comparative study explains these differences.

In the mixing-method example, qualifying prior use could allow the manufacturer to continue its existing operation without the patent owner’s permission.

The conclusion must identify the activity protected. For example, the US prior-commercial-use provision expressly limits the defence rather than granting a general licence under every patent claim. The defence also does not, by itself, invalidate the patent.

Use the records to assess whether the conditions are met

The adviser needs to connect each legal requirement to specific evidence. Technical files identify the method used; production or testing records show the activity; dates, locations and company details establish when, where and by whom it was carried out. Distinguishing experiments, preparations and commercial operations helps determine what had happened by the legally relevant date.

In the mixing-method example, the adviser would compare the dated operating instructions with the method covered by the patent, then check the batch records for evidence that the business used that method at the relevant site and time. Timestamps can support when those documents existed. The batch records and other supporting documents must still establish the operation itself. If the batch records do not identify the method used or the production date, flag that gap before relying on the defence.

Check new plans against the limits of the right

Continuing the existing mixing method and launching a changed operation are different questions. If you introduce a new mixer component covered by another patent, your earlier use of the method does not automatically address that patent. Moving production to another country or changing the method also requires checking whether the protection still applies.

Keep the adviser’s conclusion with the technical version, countries and activities reviewed. Record which prior-use right supports continued operation and which proposed changes still need assessment. Where protection is insufficient, options may include a licence, a design change or a challenge to the patent. WIPO’s FTO overview discusses these approaches.