When you apply for planning permission in the UK, you will be required to submit an Ordnance Survey map of the site where you are planning to perform your development. It is essential that this map is of the sufficient scale to allow the planning committee to get a detailed view of your project, and it is also imperative that the map is completely accurate - this is why you are discouraged from using map providers who do not offer Ordnance Survey maps. While there are some other companies that provide maps that are suitable for planning applications, in general road maps and maps used by tourists do not offer the level of detail, scale or accuracy that is needed for a planning application, so you are hereby advised not to use these.
The planning committee wants to know exactly how big your development will be, what area of land is included in it, what is in that area of land, what else will be affected by the application, and whether the application could impact on roads, sewerage, public transport, parking, or rubbish disposal.
The committee needs to feel confident that your project is safe and practical. They cannot make that decision if you do not provide them with an accurate planning application map showing all the required details. In fact, if your application is missing details - such as detailed maps - they will likely return it to you and refuse to consider it until you provide them with the information that they want to know.
If you fill out the planning application online, you will be walked through every field that you need to fill out, and alerted if you miss anything. You will also be told what attachments you need to provide in order to complete the application - things like area maps, quotes, site maps, etc. You should seriously consider applying this way because it will be much more efficient than posting things off and the application will be processed quickly and sent to the right department. This in turn leads to a quicker checking process which greatly reduces the risk of things going wrong.
If you are sending your application by post, make sure that you check it carefully. Every piece that applies to you, should be filled out and anything that is not applicable should be marked as such. The site map should be centred on the site of the project, with this area clearly marked out. If you are required to provide a site plan (not all applications are) then you should do this as well and it should be as clear as possible and to the correct scale too.
Applying for planning permission is a complex process, but it is something that must be done. If you do any major building project without permission, then the penalties can be incredibly harsh. Talk to a legal advisor today if you are concerned about whether you will need planning permission - they will help you to figure out what you need to do, and will ensure that the application goes as smoothly as possible and is processed on time and fairly.