Getting invited to a friend’s wedding is most likely exciting for people, especially since it’s basically an invitation to have fun with old friends and party on their dime. However, it’s also important to remember that the bride and groom-to-be have been spending much of the last year or so in wedding planning mode – picking out everything from wedding decoration ideas to wedding ceremony songs – meaning they’ll expect their big day to go without a hitch.

Because of this, it’s crucial that you understand the etiquette of being a guest, so the couple won’t regret having you there.

Make sure to RSVP
Sure, you might have gotten the formal invitation for the wedding, but since you’ve been discussing the big day with the bride throughout the planning process, you may assume there’s no need to send back that you’ll be attending because she knows. Wrong. According to The Huffington Post Wedding, RSVPs are not an option, they are mandatory and help the couple figure out exactly how much food, drink and other items to order.

Secondly, it might be slightly embarrassing when the bride has to call you up and ask you if you’re coming, when you know you could have just sent the RSVP back.

Don’t assume you can bring a date
You might think that in this day and age everyone gets to bring a date to a wedding, but this is certainly not the case. The best way to figure out if you can or cannot bring a date is to check the invitation itself, The Frisky reports. If the card is solely addressed to you, it’s likely you’re being invited sans a guest. However, if you’ve been dating your guy for awhile and he knows the couple, it could be OK to ask the bride and groom about whether or not he’s invited – just make sure not to get upset or question it if he isn’t.

In most cases, brides and grooms will opt to allow married couples, those who have been dating for a long time, or guests who don’t know many other people at the wedding to bring a companion. Any other special requirements or exceptions will need to be made by each couple individually, since planning a wedding is a lot of work and expensive.