On 24 May, OFSI posted on its blog an article saying that it had has received unprecedented numbers of licence applications to permit prohibited transactions or activities owing to more sweeping and far-reaching sanctions imposed relating to Russia and Belarus. Many of these applications involve UK persons who are owed money by Russian and Belarusian Designated Persons (DP) under contracts agreed before the designation of those DP and can only receive such payments once they receive an OFSI licence. OFSI has now issued a General Licence covering such prior obligations, and the post explains the requirements, including reporting requirements.
https://ofsi.blog.gov.uk/2023/05/24/prior-obligations-general-licence/