Valuables without a dedicated registry can be difficult to identify, establish ownership of, and value after an emergency or death. Make an inventory and keep supporting evidence in advance. Do not treat a single online asking price as proof of an item’s value.
Create evidence that identifies each item
Take photographs from several angles and record dimensions, weight, distinguishing marks, serial numbers if any, seller, purchase date, receipts or certificates, and who currently holds the item. Do not include the location of a safe or access codes in a file shared broadly.
Value and store the records carefully
Separate authenticated items from items that have not been verified. Distinguish an insurance value from an expected sale price, and consider an independent appraiser without a conflict of interest. Keep backup images in a secure system with a designated person responsible for access.
Prepare an inventory for future administration
Record a contact person, how to reach the place where items are stored, and how you want the property handled in a will or another document reviewed by a lawyer. If tax or a transaction is involved, check the applicable law and valuation with a qualified professional; do not infer tax treatment from the type of object alone.
Official source
Related reading
The linked video is a general discussion about financial strength before retirement. It does not cover estate inventories or the valuation of collectibles; the source above is provided for the inheritance-tax legislation.