If you ever plan to buy a house, establishing a track record of past payments is essential, because it proves to mortgage lenders that you’ve paid people back (which means they’ll be more apt to loan you money for a home).

Still, if you have no credit history—because you’re young or just never bothered—how long does it take to build it from scratch?

Here’s the straight dope: Done right, it can take as little as six months. Done wrong? It can take several years. So if you’re in a rush to establish credit to buy a home, you’ll want to know the right way to go about it! Heed this advice to learn what to do.

Building credit: A timeline

At a minimum, you need to open at least one credit card in your name. From there, you just need to make a purchase using the card, and then make a payment. Once you’ve made your payment, your creditor will report your payment to one or more of the major credit bureaus (TransUnion, Equifax, and Experian).

“Typically, it takes at least three to six months of activity before a credit score can be calculated,” says Tracy East, director of communication at Consumer Education Services in Raleigh, NC.

Once you’ve established credit, you still have some work to do. Credit histories are scored based on performance, much like the grades you got in school. Healthy credit behavior—like on-time payments and staying well below your credit limit—lead to a higher credit score.

What’s more, there are two types of scores: VantageScores and FICO scores. Some mortgage lenders may look at a VantageScore, but FHA lenders are required to use FICO scores.

“After opening their first credit account and beginning to make timely payments, it will take at least three months for the person to generate a VantageScore, and six months to have enough information to create a FICO score,” says Martin Lynch, compliance manager and director of education at Cambridge Credit Counseling of Agawam, MA.

And the longer you demonstrate good credit behavior, the higher your score can climb from there. In other words, a couple of on-time payments is nice, but years and years of on-time payments is far more impressive, and reflected in your score accordingly. In fact, the length of your credit history can count for as much as 15% of your credit score.

What credit score do you need to get a mortgage?

Your initial credit score when building credit will typically be in the 660s, which is considered on the low end of “fair” (fair scores range from 650 to 699). It could be just enough to buy a house with some lenders, but not all, because lenders vary regarding the minimum credit score they will accept.

You should also know that while a “fair” score may get you a mortgage, it won’t qualify you for the best mortgage—in terms of interest rates and other deals. To get better mortgage rates, you will need a good score (700 to 759) or an excellent score (760 or higher). Unfortunately, achieving these scores will take (you guessed it) more time.

How to speed up the credit-building process

To establish a payment history, use your card reasonably. Make payments on time (or early, if possible). Setting up automatic payments can help. East recommends keeping your balance below 30% of your credit limit and, ideally, paying it off in full each month. These simple steps will eventually push your score from fair to good to excellent, allowing you to get the best rates for your mortgage.

Here are some other ways to speed up the credit-building process and ensure your credit history and score get off to a good start.

• Become an authorized user on someone else’s account. This can be a parent, friend, or relative who has had the account for at least a few years and has a good payment history. You don’t need to use the account or even have a card. Once you’re added as an authorized user and that fact is reported to the credit bureaus, it will instantly affect your credit and may generate a score if you don’t already have one or, at least, give it a boost.
• Get a secured credit card or loan. If you’re having trouble qualifying for a traditional credit card, try for a secured credit card, which is “secured” by a deposit. This means that if you default or stop paying, your deposit will be used to pay off the account. This lowers the risk involved for the lender, which makes it more likely to offer you credit even if you don’t have an established credit history.

Also know that when it comes to mortgages, your credit score is just one piece of a larger puzzle. According to Lynch, your lender will also look at your employment history, how long you’ve lived at your current residence, and your credit references.