Honesty always pays. It is still a best policy. If you are dishonest or tell a lie, then there is a very good chance you would be found out. And your dishonesty will come back to hurt you. That is why it is probable best to tell the truth most of the time.
Honesty creates favourable conditions for building trust. If you want to have a good relationship with someone who you think would be your good partner, you have to be honest to gain the trust and respect of them. Again if you have done something wrong, then you have to tell the truth to get it solved easily.
Dishonesty or telling a lie makes your situation worst. If you lie about something, then you have to make a lie to cover it in vain because truth cannot be hidden in the long run. However, sometimes due to security purpose and for not hurting the feeling of others, it might be best to tell a small lie.
Always remember, temporarily you can gain a support of someone by the glamour of untruth and dishonesty, but, in the long run only the truth and honesty prevail and win.