Not all works require a planning application. If your proposal is not development, it will not need planning permission.
The Government has produced useful guidance which explains when planning permission is required
In some cases the Government grants planning permission for smaller works and changes of use (known as permitted developments). These can then take place without submitting a planning application.
To support business recovery and aid social distancing the Government has granted planning permission for the temporary uses of land for an additional 28 days between 1st July 2020 and 31st December 2020. In combination with the 28 days already permitted, this means up to 56 days of temporary use in total may be permitted (subject to certain restrictions). Permanent works and buildings (including hard surfacing) still require a planning application.
The Government has also granted planning permission to for markets to be held by, or on behalf of, Parish, District and County Councils at anytime up to 23 March 2021.
Works affecting the historic character and interest of listed buildings or certain structures around and near listed buildings, are subject to special controls. Carrying out works to a listed building without securing the necessary consents is a criminal offence. For more information see our listed buildings page.
If you would like a formal written determination as to whether a planning application is required you will need to submit an application for a Proposed Lawful Development Certificate - Proposed Use. A fee is payable for these applications.