Most estates in the UK do not pay inheritance tax.
That is the first thing to know. Not later. Not after forms. Not after panic. Right now.
Inheritance Tax is real. It can be significant. But it applies to a minority of deaths. Most people will never encounter it in practice.
If you are reading this in the days or weeks after a death, slow down. Nothing needs to be decided today. Very little needs to be decided this month.
Inheritance Tax is charged at 40% on the value of an estate above the available threshold. As of now, the standard threshold is £325,000.
There are additional allowances in common situations. Transfers between spouses or civil partners are usually exempt. A residence allowance may apply when a home passes to direct descendants.
Because of these rules, the majority of estates fall below the taxable level.
Source: https://www.gov.uk/inheritance-tax
These are factual questions. They can be answered slowly. They do not require urgency or fear.
Inheritance tax is not assessed in the first days after death. It is not triggered by delay. It does not punish you for taking time to grieve.
Inheritance Tax is linked to probate and estate administration. That process takes months. Often longer.
Some tax may be due before probate is granted. That does not mean you must rush decisions. It means information is gathered and assessed in stages.
No one benefits from panic. Mistakes made under pressure are usually more costly than delay.