What it is. Paying a company to add you as an authorized user on a stranger's credit card purely to put their history on your report.
Why it's risky. It often costs hundreds to over a thousand dollars with no refund, and the effect typically disappears within a month or two after you're removed. Lenders and scoring models increasingly discount authorized-user accounts that don't reflect your own behavior, and presenting borrowed history to a lender can look like misrepresentation. Some of these operations also run alongside illegal CPN or synthetic-identity schemes.
What to do instead. If you want the authorized-user benefit, get it for free from a trusted person with an old, clean, low-balance card (Course 2 · L9) — and build your own accounts, which is what actually lasts. Before acting, check with FundFoundr.