I share @Salma ’s understanding that a declaration of an inheritance received by a French resident is obligatory.
However I’m sure I’m not the only one who appreciates one of the ‘endearing’ features of life in France, being the ‘daylight visible’ between the strict law of the land - and its actual application. There are enough examples available (@PeterJ ‘s example is timely) of (some) tax offices advising, or tacitly accepting, that they don’t want to go to the time and trouble of opening a dossier, on a case with zero French tax at stake. They presumably have bigger fish to fry. Accordingly those offices do not seem to require a declaration of inheritance from UK estates with no French assets.
Personally what I think I would probably do if I ever find myself in this situation is to attach a wording in the ‘Mention Expresse’ section of my income tax return, to show good faith, and to give the tax office the opportunity to ask for more information - should they wish. There is little to lose by so doing.
Here’s one I made earlier…
“On XX/XX/2026 I received an inheritance of UK property valued at xx xxx €. The deceased,(insert full name, last address and date of death), was at all times resident in the UK, and his/her estate was entirely comprised of UK situs assets. Under Article IV(a) of the 1963 UK/France Estate duty treaty, the inheritance is only taxable in the UK. The entire estate has been declared to His Majesty’s Revenue & Customs (HMRC) by X’s Executors, and has been fully settled to HMRC’s satisfaction. HMRC’s tax reference for dealing with the estate and its UK inheritance tax liability is xxx/xxxxx. Please let me know should you require any additional information .”