If you want to be certain that the existing use of a building is lawful for planning purposes, or that your proposal does not require planning permission, you should apply for a Lawful Development Certificate (LDC).
It is not compulsory to have an LDC but Coventry City Council will no longer provide written advice on whether a proposal requires planning permission. So, if it is important for you to have that clarification, you should make a formal application.
The LDC process can also be used if you want to confirm that the current use of a property is lawful.
Please be aware that a planning permission does not always confirm the use of a premises or site as it may not have been implemented or the use may have changed since planning permission was given.
For further information on making an application please look at the planning practice guidance.