Most planning applications are submitted online and for this reason, they can also be viewed online. This applies to any application and decisions made since 1973. You may even be able to download plans, maps, decision notices, consultation responses and comments if the application was made in 2010 or later.
In order to view a live application, you can visit the Government website, accessible via https://www.gov.uk/search-register-planning-decisions, and enter the postcode used in the planning permission. This should take you to the correct borough council’s website, from where you can navigate to the planning permission page/tab and follow their search filters to find your planning permission in the database.