The title of this post is a question and let me first start with the answer. The answer is credit cards. And not only are credit cards faster, you actually cannot attain a real, solid, credit with only mortgages, ever (even if you have mortgages opened for many years).
I have seen many cases where people were scoring below 700 and they had mortgages for over 10 years with no late payments. Why is it so? Let me explain.
The difference between a revolving loan and an installment loans
There are two types of loans which a person can possibly have. The first type is an installment loan, for example: mortgages, auto loans, or any loan that has a fixed amount that needs to be paid every month. Another type is the revolving loan, for example: credit cards or loans that don’t have a fixed amount that needs to be paid every month.
Installment loans are usually mortgages, car leases etc., that are backed with collateral and not only a personal guarantee. Revolving credit will usually be a credit card etc. that is not backed with a collateral.
Credit cards have a bigger weight on your score
When credit models calculate a credit score, credit cards will carry a bigger weight on your credit score. Why? Because at the end of the day, a person is more likely to pay his mortgage than his credit card bill. If he doesn’t pay his mortgage he loses his house but when he doesn’t pay his credit card bill, he does not lose anything (except for his credit). So obviously, a person who has never been late on a credit card, displays his trustworthiness more than when a person always was on time on his mortgage.
Another reason a credit card carries more weight on your credit score than a mortgage does, is because with a credit card the amount due changes month after month. That makes it harder to manage than a mortgage that has a fixed amount due every month. Understandably, properly managing a credit card for many years shows more responsibility than properly managing a mortgage. Therefore, credit models will give a better score for the credit card manager than for the mortgage manager.
The best is to have both
For an optimal credit score, it is best to have both installment loans and revolving loans. Credit models will want you to prove yourself capable of handling different types of loans. So having both a mortgage (or any installment loan) mixed with some credit cards is the best way to go.
I usually recommend having a minimum of three tradelines including a mix of two revolving loans (credit cards, etc) and one installment loan (mortgage, auto loan, etc).