I have lost or forgotten my passcode which I need to erase all the data on my iPhone 4 before selling it. Is there a default code?
iPhone 4, iOS 7.1.2
There isn't a default code. You need your Apple ID password -- same one you used to log in here unless you have more than one Apple ID. If you have forgotten the password, the following has help: If you forgot your Apple ID password - Apple Support
I know my apple password. However when I try to "Erase All Content and Settings" on the reset page I am directed to another page that requires me to enter a Passcode. It only has a numeric keyboard. Hence my frustration as I have no idea what the passcode should be.
That sounds like a Restrictions passcode (also known as Parental Controls). If that's what it is and you don't know the code, the only option is a restore to factory settings: Use iTunes to restore your iOS device to factory settings - Apple Support
Also, you can verify whether Restrictions are on or not. In iOS 8 if you go to Settings > General and scroll down to Restrictions it will show on or off. I don't remember iOS 7 but it may be similar.
Thanks for your help. All OK now
did you find this iPhone?
how do I find out my passcode that I need to erase all data on my phone
