As you are going to list a trademark for sale, we will have to verify you are legally in a position to sell that mark. You will only have to verify the account once.
You will need to prove that you are either the individual, business or organisation listed at the IPO as the owner. If it is a business or organisation, you will need to show you have the legal authority to sell the trademark on behalf of the business – either as a director or owner of that entity or as an individual empowered by your position to list it.
In all cases any documentation provided must show the correct name and address of the trademark owner as listed at the relevant IPO. What you need to provide depends on what role you have.