Do i need planning permission to put a business sign on my house wall?

Yes. Depending on what kind of business you're running from home, and how big of an area of your house this covers, you may also need the council's approval to run your business from home.

Call up your council to discuss details.
I think you do. Also make sure you are totally Legal with taxes etc, because your neighbours might report you. Best of Luck
Yes but its a different type of form to the one you use for an extension. Get in touch with your local council and they will be very helpfull.

(just a little hint - state that it is not illuminated in the application as this will be more appealing if you are putting it on ur house
Yes, signs need planning approval. Assuming the sign is advertising a business based in your house, you may also need planning permission for "change of use", assuming that up to now your house has been used exclusively residentially. Get in touch with the planning office for advice.
NO ! You can put anything on your walls,,, It is your house. However you cannot operate a business which means take money for a service rendered without a federal tax i.d. number and quite possibly a license of some sort from your city, depending upon what the business is.

I hang signs anywhere I want on my property, walls included.
In the UK, you probably do.

The local planning authority will be quite happy to discuss it with you, and advise you on whether you need permission or not.

However, if you are running a business from your home you may be infringing the existing permission. You may require "change-of-use" planning permission - depending on how much space the business uses up, and other factors. Adding a sign, or asking about one, may alert the planning authority to the fact that you are running a business, forcing you to cease or gain the appropriate permissions.
Take my advice, don't put up a sign.
First, I suspect you may already be runnning a business from home - possibly against Planning Regs.This will bring an Enforcement Officer around to check on the situation.
If it all possible, he will try to force you submit a Planning Application for several things, e.g. erection of a sign, use of residential property for business use, to name but a couple
i think so