PHOENIX — Arizonans are now paying more money to state and local governments for the items they’re buying online.

The Arizona Department of Revenue reports it has collected an extra $51.5 million in the first two months a new law has been in effect. Of that, $23.4 million is going into the state treasury, with the balance parceled out among cities and counties.

What makes that number so impressive is that budget analysts had predicted the net gain to the general fund for a full fiscal year would be just $85 million.

And the collections reported so far don’t even represent the Christmas sales that were made in December.

The new cash is not a new tax on Arizonans — at least not strictly speaking.

What it represents is Arizona’s effort to take advantage of a 2018 U.S. Supreme Court decision which concluded that states are free to levy their taxes on all sales made into the state, regardless of the source.

Prior to that, the law had been that a business had a “nexus” to the taxing state, usually in the form of a physical presence.

So purchases made from, say, a Target store always have been subject to the state’s 5.6% tax plus applicable local taxes. Ditto to purchases from Target.com given that retailer’s presence.

But that online retailer in New York state who sold and shipped you a $300 camera collected neither that state’s sales tax nor the Arizona levy.

All that has now changed.

As of Oct. 1, Arizona began requiring retailers who make at least $200,000 in direct sales into Arizona to begin charging what is technically called the state’s “transaction privilege tax.”

Put simply, that purchase of a $300 camera online from one of the retailers required to collect the levy would add $16.80 in state taxes. And someone living in a city and county with a combined local rate of 4% would find another $12 tacked on.

Ed Greenberg, spokesman for the Department of Revenue, said his agency has already issued about 2,100 of these “remote seller” licenses.

More retailers will soon be subject to the levy. Later this year the threshold for having to collect Arizona taxes goes to $150,000, dropping to $100,000 in 2021.

So why isn’t all that extra money collected a tax hike? Well, it’s a simple matter of compliance — or not — with prior law.

Shoppers who go online — or travel elsewhere — to buy everything from clothing to furniture and electronics legally have been required since 1955 to compute what they would have paid had they purchased the items in Arizona and then send that amount off to the state every month. Much of the purpose was to eliminate the advantage that out-of-state retailers had over the brick-and-mortar stores in Arizona.

How many Arizonans actually do, however, is another question.

The last budget year, Arizona  collected slightly more than $326 million in use taxes, a small fraction of the $7.4 billion taken in, some of which is shared with local governments.

But state officials have estimated more than 99% of that comes from businesses who not only have a more formal process of reporting but, potentially more significant, also are subject to audits.

There are no firm figures on how many individuals are complying with the law or, more to the point, are ignoring it.

The new tax on out-of-state retailers is designed to make up for that lack of compliance and narrow the gap between Arizona retailers and their out-of-state competitors.

There is, however, a flip side to this for Arizona businesses who have long been selling retail items to customers in other states. They now are going to be required to comply with similar laws being enacted elsewhere.

As it turns out, at least some online purchases made by Arizonans already were being taxed, even before the new law kicked in.

Amazon began collecting state sales taxes in 2012 on its own products and those of Amazon affiliates after reaching an agreement to settle a $53 million assessment made against it by the Department of Revenue.

For years the Seattle-based company argued its online sales were not subject to the levy because, unlike a place like Target, it did not have retail outlets in the state.

What it does have, however, are distribution warehouses where goods from elsewhere are processed and sent out to Arizona customers. And that, revenue officials argued, provides the legal “nexus” to the state.

But that agreement did not cover situations where Amazon was simply a platform for other out-of-state retailers. The new law should fill that gap.