A colleague asked me today if brides and grooms must invite single guests with a date to a destination wedding. The bride in this discussion said she didn't have to invite dates if a friend was single and my friend said for a destination wedding couples should invite singles with a date - or at least she thought "and guest" was a given.
Brides and grooms are not required to invite single friends with a date. Here are the parameters you may want to follow when putting together your guest list:
1 - Married couples are both invited, even if you don't like your friend's spouse
2 - If a couple is living together they are both invited
3 - You can determine a time frame for a couple dating to decide if you want to invite them together. I suggest that if a couple has been dating for six months or longer they are both invited to the wedding
Here are some separate issues you may want to consider:
If all of your friends are in relationships except for one or two then you may want to invite them with a date so they don't feel like the odd one out.
If you are inviting a person that you know doesn't know anyone except for you or the groom, you may want to invite him or her with a date.
I suggest asking a sibling if he or she wants to bring a date even if he or she is unattached.