Hi @Caylan Deal. In 2019 some counties switch to what we call the "new system." It was elective. Jefferson County switched in 2022. Most counties are on the new system. I few, such as some of the smaller rural counties, plus Lee County (Auburn University) and Houston County (Dothan) still use the old system.
Under the old system, investors bid up the auction price. The redemption rate was 8% on the taxes plus some portion of the overbid. Unsold properties went on the Alabama Department of Revenue inventory, where they could be purchased over the counter. Some wholesalers obtain price quotes from ADOR and you can buy from their websites at a markup. Under the old system, investors get a tax certificate. It entitles them to possession. That is a tricky issue too long to discuss here. Read some of my other posts and forum answers. Bidding is at in person auctions at the county courthouse. Winner bidders pay the taxes each year unless and until there is a redemption. Three years after the auction they can surrender their tax certificate and get a tax deed. Former owners usually still have redemption rights. The investor does not get clear title until it obtains a quiet title order from a judge after a lawsuit, or it gets releases or quitclaims from everybody with redemption rights to the property, giving up their rights.
Under the new system, bidders bid down the interest rate they are willing to accept if the property is redeemed. It starts at 12% and can go down to 0%. Winning bidders get a tax lien. They are not entitled to possession. They do have a right of first refusal to buy the next year's tax lien at the same interest rate. Bidding is usually online, at govease.com. Unsold liens can be sold individually by the counties, if they want to bother with it. Usually they just wait until the next year, and sell two years liens at once. The law will change on 10/1/24. After that date, investors must wait four years after their first auction, and must own all of the tax liens in the meantime. After that critical date, they can file a foreclosure lawsuit to foreclose their liens. If nobody redeems in that lawsuit, someone can still demand a public auction. The judge will order a public auction, kind of like a bank foreclosure auction, and the highest bid wins. Out of the winning bid, the investor is paid their taxes, plus interest, plus legal fees, plus auction fees. The rest is divided among people with redemption rights. The investor has the opening bid equal to everything owed to it. If there are no bidders, the judge will quiet title to the property in the investor and order the clerk of the court to issue a clerk's deed. The investor can bid against other bidders.
That's it in a nutshell. There are many different successful strategies depending on your cash, borrowing ability, rehab skills, time, local contacts, or lack of any or all of them.