By Ivy JacobsonYou may have anticipated some tricky trade-offs when creating your guest list, but have you thought about plus-ones yet?No one understands better than we do the stress and nuances of planning a beautiful, personal wedding within your budget. One of the first big steps in creating that budget is putting together a guest list that works for your venue—plus-ones included. So how do you tackle this hot topic? Start by going back to the basics:  Each head count costs money, and venues hold only a certain number of people. You’ll need to tread carefully and follow these tips so everyone will have a wonderful time at your wedding.Who should get a plus-one?Anyone Who’s MarriedAlthough we love to break some traditional rules, it’s always best to invite both parties in a married couple, even if you’re closer with one person than the other, or if you’ve never even met someone’s spouse. Think about it—would you want to attend a wedding without your spouse? It’s polite to acknowledge that even though you’ve never met your aunt’s new husband or your future father-in-law’s boss’s wife, you respect their union.Anyone Who’s Engaged, Lives Together or is in a Long-Term, Serious RelationshipAny couples who are engaged, live together or who have been dating over a year should get a plus-one. In this day and age, lots of couples live together before they get married—or never get married at all—so acknowledging their commitment is the right thing to do. While you can use your judgment with couples who’ve been dating over a year—say, your 16-year-old cousin and his girlfriend—you and your partner should be able to tell if it’s a serious relationship. If not, err on the side of caution and give them a plus-one.Your Wedding PartyExtending a plus-one to everyone in your wedding party is a courteous move they’ll definitely appreciate. This doesn’t mean you have to force each bridesmaid and groomsman to bring a date to your wedding if they don’t want to (there’s a chance they’ll decline anyway), but it’s important to make the offer because they’ve been there for you from the start. Shopping, planning your bachelorette party, fastening the 150 buttons down your wedding dress, ushering your grandparents down the aisle, calling the limo company last minute—the list is endless, which proves just how much these friends have mattered throughout your wedding prep process. It’s important to remember they’ve not only given you their time, love and energy, but they’ve also spent a lot of money on attire, lodging and transportation, maybe for multiple events. Trust us on this one—they deserve a plus-one.A VIP Guest Who Won’t Know AnyoneSay one of your very best friends from childhood who lives across the country is a VIP guest, and single. While she knows you and maybe your parents and partner, none of you are likely to have much time to spend with her. Give important guests who fit this description a plus-one so they can feel comfortable and have fun too.Who doesn’t need a plus-one?Guests Who Are Casually DatingIf the guest in question seems to have a new significant other every few months or hasn’t been dating the same person for more than a year, giving them a plus-one isn’t a priority, although it is thoughtful if you have the budget to do so.CoworkersCoworkers can be a tricky guest list category altogether, even without the issue of plus-ones, so let’s back up for a moment. The easiest way to avoid any drama is to not invite any coworkers at all. That way nobody feels left out. But if you’re close to some of your coworkers (you socialize outside the office and text or call their cell phone) and everyone knows it, it’s fine to invite them. Just don’t hand them their invites at work or make a big deal out of it. Keeping wedding talk to a minimum at the office is smart anyway. However, if you work on a smaller team and are considering inviting a handful of coworkers (that you aren’t friends with outside of work), invite the entire team or skip them altogether. This goes for plus-ones too. Whether you invite your work besties or your team, if one person gets a plus-one, then everyone else should too.As for your boss, invite him or her if you have a friendly relationship, along with a plus-one. If you don’t, you’re certainly not required to ask them to attend. Often, unless you’re close, your boss will acknowledge your thoughtfulness, decline, and send a gift.Single Guests You’re Not Especially Close to and Who Will Know Other GuestsIf your mother-in-law insists that cousin Olivia needs an invitation (even though your partner hasn’t seen her in 10 years), it’s okay to not give her a plus-one if she’s not married or in a serious relationship. While you may not be able to afford extra guests for everyone, it may start a fight if you want to cut people from your guest list just because you can’t let them bring a date (especially if they’re on your in-laws’ list). Deal with this problem on a case-by-case basis, then carefully consider where to seat them at the wedding if they attend.But if your budget just won’t allow certain guests to have plus-ones (and you want them to bring someone), this is where having a B-list comes in handy.Let’s Talk About Your A- and B-ListsHaving two lists is how you’ll be able to invite the most people without increasing your budget or having to find a larger venue. Here’s how it works: Your A-list consists of the must-have invites you couldn’t imagine not having at your wedding, like your family members and close friends, and their plus-ones. They’ll receive your first round of invitations. Anyone not essential (no, we don’t mean people you don’t like, but rather colleagues you might be able to skip) should be added to the B list, and their plus-ones. These are people you would enjoy having at your wedding but who cannot be extended an invite in the first round. It’s completely fine to add plus-ones to your B-list too, and if it turns out that you do have the budget for your nephew’s new girlfriend to come, you can always invite her at a later date.If you start getting RSVPs and it turns out you have enough “regrets,” (between 10 and 20 percent of those invited will decline) then you’ll start sending invites to your B-list in order of importance. That said, one of the dangers of a B-list is sending invitations out with a too-tight RSVP date for your new additions. To avoid this, consider sending out your first set of invitations a little earlier (instead of six to eight weeks before the date, aim for 10 weeks). If this is impossible, consider ordering some invitations with a later response date.And so things don’t get sticky…Order extra invitations.If you think you might be sending a second set of invitations for a B-list, prepare for it ahead of time. Not only will it make the process smoother, it’ll save you some serious cash since buying invitations in small batches is much more expensive than ordering them in a single shipment.Be realistic about the number of guests and plus-ones to avoid stress later on.Crunching the numbers isn’t the most glamorous part of wedding planning, but there is a figure you really can’t avoid: your guest list count. Your budget and the venue size are the main factors that should play into this decision. Each guest adds to the number of plates your caterer will prepare, favors, chair rentals and how much cake you’ll need. Choose a number that’s larger than your venue’s capacity and you’ll be holding your breath every time you open an RSVP. It’s much better to keep your number on the conservative side. If there’s room in the budget or you end up having more space than you thought you would, add later on. Make it easy on yourself and use The Knot Budget Calculator to play around with the numbers and see how much you can save or spend by subtracting or adding from your guest list.Include names on the response cards.Yours wouldn’t be the first wedding where a guest crams two (or three or four) plus-ones onto one line, even though the invitation was made out to one person. The way to avoid this problem is to print the guests’ names onto the RSVP card. Do this and there’s almost no way anyone can force an invite on you. If for some reason you still get an extra write-in, don’t take their faux pas personally. Instead, politely call and tell them the deal: You’d love to have everyone, but budget and space mean it’s just not possible. Then take the conversation in a totally different direction.Make sure you know the name of every plus-one.Play detective and know the name of every plus-one so you can have it written and spelled correctly on the save-the-date, invitation and escort card. Even if you have to fall down a Facebook rabbit hole or make a call, it’s 100 percent worth it, and the polite thing to do. It looks so much better than “and Guest” on all stationery, and all parties will appreciate your extra legwork.