Read the complete schedule
A headline spread describes only one potential cost. Your checklist can also include commissions, overnight financing, currency conversion, inactivity conditions and withdrawal charges. Look for the current schedule for the precise account type you are researching.
Write down the assumptions
Costs can depend on the instrument, account, time and trade size. Keep those assumptions with your notes. Do not present one observed spread or a promotional minimum as a typical all-in cost.
Document what is missing
If a fee or calculation method is unavailable, mark it as unavailable and seek clarification from the source. Leave spreads, deposits and execution statistics unreported when supporting evidence is unavailable.