If you are using your work and personal github accounts locally, you'll need a little more setup to have both ssh keys playing nicely together.

Let's say you already have 2 keys configured as follows:
```
~/.ssh/id_rsa       # personal
~/.ssh/id_rsa_work  # work
```
And they're both loaded in the ssh-agent
```
$ ssh-add -l
... .ssh/id_rsa (RSA)
... .ssh/id_rsa_work (RSA)
```

Update your `~/.ssh/config` so that your work key uses an alias for the host.
```
# Personal
Host *
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_rsa

# Work
Host work-github.com
  HostName github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_rsa_work
```

Now when you clone repositories, you'll need to specify them with the `work-github.com` host name.
```
git clone git@github.com:workorg/workrepo.git        # wrong
git clone git@work-github.com:workorg/workrepo.git   # right
```

If you find that annoying or hard to remember, you can set a global git config like so:
```
git config --global url."git@work-github.com:workorg".insteadOf git@github.com:workorg
```

Now you can do:
```bash
~ $ git clone git@github.com:work/workrepo.git
~ $ cd workrepo
~/workrepo $ git remote -v
origin  git@work-github.com:work/workrepo.git (fetch)
origin  git@work-github.com:work/workrepo.git (push)

~ $ git clone git@github.com:notwork/notworkrepo.git
~ $ cd notworkrepo
~/notworkrepo $ git remote -v
origin  git@github.com:notwork/notworkrepo.git (fetch)
origin  git@github.com:notwork/notworkrepo.git (push)
```
The remotes for your existing work repositories will automatically be updated too!