Record the license
For IP that is registered in the UK, a licensee can record their interest as licensee with the IP Office. A license that is registered in this way will be binding on any successor in title to the UK registered IP right. If the license is not registered at the IP Office, a license granted by the owner of a UK registered IP right will still bind any successor in title to the UK registered IP, except a purchaser of those rights who buys them for good value, in good faith and without notice of the license. This means that, if an insolvency office holder was to try to sell on the registered IP to another party as part of either a going concern sale of the business and assets or a break up sale, as long as (i) the license had not been disclaimed or terminated and (ii) either the new owner has actual notice of the license or the license is recorded on the public register, then the new owner of the UK registered IP right would be bound by the terms of the license. The position in relation to rights registered in other countries but which are licensed by an insolvent UK licensor would depend on the local rules around registration of licenses.
Contractual considerations
Structural/pricing considerations