Have you ever taken on a client and realized you didn’t charge enough? Or maybe, you took on a client and realized that, no matter how much you charged this person, it would never be enough?

If you’re a copywriter, this is the client who demands three or four more revisions than any other client you’ve ever had. If you’re a web designer, this client demands a complete redesign a week before you go live. If you’re a graphic artist, this client wants “just one more” look for his logo—five times more than you ever agreed to do.

What I’m describing is called scope creep.

For large projects, scope creep occurs when “new features are added to product designs that have already been approved, without providing equivalent increases in budget, time and/or resources.” Scope creep happens when a project is already in progress, not before a project begins. For smaller projects, you can think of scope creep as any new asks by a client without attendant increases in your budget.

I’m a freelance writer and editor. When I first got started, I didn’t understand the importance of writing clear quotes for clients. As a result, I faced scope creep a lot. The most common one that I faced was the “one more draft” request. Usually a client knew better than to ask me to read an entire piece again—even to grabby clients an entire re-read seemed like a bridge too far. But grabby clients would ask me to re-read an opening, or a closing, or just to first sentence. “Just one more glance—it won’t take you any time at all.” And, eager to get a strong referral or testimonial, I’d say yes. The problem with saying yes to grabby clients, though, is that they grab more, and more, and more. That full reread that seemed like a bridge too far? After a while it wasn’t too far any more.

So I asked around to other small business owners. How did they deal with grabby clients? A friend who owns a production company taught me two important things: the term “scope creep,” and the key to writing detailed quotes.

Here are some suggestions that I can pass on to you.

Write clear quotes, then get clear agreement

I no longer make the rookie mistake of jotting down in an email a sentence or two about the work I’m going to do. Now, I use the quote function in my bookkeeping software to write formal quotes, even for jobs that seem small.

Often it’s the small jobs that sprawl in scope once they’re underway.

Include ways to add scope

In my quotes, I always include instructions for how to add scope. There are two extras that editing clients tend to ask for: in-person meetings to discuss my edits, and a reread. Copywriting clients ask for a variety of add-ons: more words, more research, stock photos, links to other sites. All of these add-ons go in my quotes as add-on items that clients can pay for.

By providing add-on items in my quotes, I’m sending a variety of messages. First, I’m advertising that there are other services my clients can buy from me. Often, clients end up buying add-on services once they see them in the quotes. I’m also indicating that I’m flexible—so long as the budget is also flexible.

Provide written updates

Scope creep happens because of poor management—by you, the manager. Sure, the client is grabby. But you’re the one who didn’t manage the project and the client well.

At this point you might be saying, “I know how to manage a project. How do I manage a client?”

Managing a client is another form of “managing up.” Your clients’ happiness with your work is your job to manage. One of the reasons why clients ask for more is because they do not understand what they are already getting. Make sure they know.

For example, keep your client happy with the work you agreed to do—the work they’ve already paid for—by keeping your client up-to-date on the work’s progress. If the client knows what the client is getting, they’ll be less likely to ask for more for free. They might ask for more, but when you ask for more money, they’ll understand why.

Bonus: You’ll be surprised by how few nagging emails you receive if you send update emails first. In fact, write into your quote that you send update emails at a certain day and time every week—then your clients will be less likely to bug you for updates. Then, spend five minutes writing a preemptive project update email, and save yourself an hour-long phone call on the project’s status.

Clients who are in the dark about the work you are doing cannot understand how valuable the work is. In turn, they can’t understand why you would need more money when they increase the scope of the work. Make sure your clients are never in the dark.