If outfits for the groom and men of the wedding party are rented, it is the best man’s responsibility to pick the suits up and return them after the wedding, being sure to check all pockets for personal belongings. Each man will pay for the rental of his own outfit.
On the wedding day, the best man will help the groom dress. He should check out the groom’s and his own clothes and accessories well before that day. He should put everythingstuds, shirt, tiein one place. This is especially important if he is dressing elsewhere. He also takes the wedding ring to the church in a safe pocket or on his little finger, if it will fit.
The best man makes sure the groom has obtained the wedding license. The best man takes it to the church himself. After the wedding, the license must be signed by the clergyman and witnesses, most likely the best man and maid of honor.
Source: http://www.bukisa.com/articles/656599_the-best-man-duties-in-the-wedding
