"On behalf of the bowling club, we would like you to accept this small gift." "We collected money on behalf of the homeless. "Mr. Roberts cannot be here, so his wife will accept the prize on his...
If someone is not available to speak for themselves, a person might say "on the behalf of *so and so* I would like to thank you...", or "on the behalf of *so and so* I am informing you...", or "on...
Indemnity, indemnify (as I understand it) is protection from loss, and to make whole, after a loss has been sustained.
On Behalf of would be the person the sum is being paid for/in your...