Hi John and Fiona,
Wow, we are very happy to hear that your carrier has provided 80% of your content limit without requiring a detailed inventory to support this advanced payment. This percentage is well above and beyond what the carriers are required to provided in a declared disaster zone and it sounds like your carrier is wanting to reduce the emotional stress of this disaster event on you and your family and adjudicate your loss quickly.
It is really up to you to determine whether or not you feel that your lost contents exceed the value already provided by the carrier (your 80% content limit). In order to secure this remaining amount, you would need to itemize your content inventory to show the carrier that their initial 80% payment is not adequate and your lost contents are valued higher. Some things to consider in this process:
-the inventory itemization process can be time consuming and emotionally draining
-the remaining 20% could be a substantial amount of money, depending on your policy limits and personal property inventory at the time of the fire
You can certainly ask your carrier to work with you and provide your policy limits, given magnitude of your loss and your situation. UP has a great letter that you can modify, asking your carrier for these policy limits:
https://uphelp.org/claim-guidance-publications/sample-letter-asking-for-a-personal-property-claim-settlement/
UP also has a great resource to assist you with the inventory process itself:
https://uphelp.org/claim-guidance-publications/home-inventory-and-contents-claim-tips/
Ultimately, we encourage you to make the best decision for you and your family. Stay positive, UP Staff!