On Black Friday, we call for the reform of Colorado’s mind-boggling sales tax system.

State and local governments in Colorado that depend on sales tax revenue have more than the usual reasons to feel good about the holiday shopping season that begins unofficially on Black Friday.

If the National Retail Federation and other forecasters are right, national retail sales this year are poised to surge. On top of that, a U.S. Supreme Court decision has allowed states to plug a longstanding loophole allowing many online retailers to avoid collecting tax from their customers.

We’ve long supported leveling the playing field in this way between online stores and bricksand-mortar cousins. This welcome reform carries a special risk for small local retailers, however, that public officials need to address. Colorado’s uniquely complex sales tax system, with nearly 700 different sales-tax combinations depending on how cities, counties and special districts overlap, is likely to burden small firms in a morass of red tape.

They will need to figure out how many sales tax licenses they need and from which jurisdictions. And they must learn how to interact with the 73 cities and two counties that, as a Denver Post article explained, “do their own collections, audits and set their own rules for what is taxable and what isn’t” rather than allow the state Department of Revenue to handle collections for them.

Welcome to a costly accounting nightmare.

To its credit, the Department of Revenue recognizes the potential downside to the new rules, which go into effect Dec. 1, and has taken steps to soften their blow. Companies can keep 3.33 percent of the tax revenue they collect, which should help offset their costs. In addition, a grace period through March 31 will protect those who inadvertently collect the wrong amount.

But more can and should be done. For starters, why should small in-state retailers face more burdensome rules than their counterparts from out of state who sell to Colorado customers? Retailers with no physical presence in Colorado and who have less than $100,000 in annual gross sales and fewer than 200 transactions in this state do not have to collect and remit sales tax. At the very least, the same sales and transaction thresholds should apply to Colorado-based retailers, but currently do not.

It’s also time to build a one-stop sales tax portal for Colorado so businesses don’t have to deal with multiple bureaucracies and different forms. A legislative task force created last year and charged with looking into ways to simplify sales and use tax collections appears to have homed in on this idea. State Rep. Tracy Kraft-Tharp, D-Arvada, has said the task force is planning a bill next session that would authorize the Revenue Department to put out a request to firms that could provide such a system.

In the meantime, we suggest home rule governments go easy on small companies that never needed a sales tax license until now. Or follow the lead of the Arvada revenue manager and pledge to offer the licenses for free.

Colorado’s system of layered tax rates and special exemptions is such a muddle that it cries out for deeper reform. Unfortunately, the Taxpayer’s Bill of Rights and special pleading by numerous interest groups makes the sort of sweeping simplification that the situation calls for a long shot.

But that doesn’t mean lawmakers should throw up their hands in despair. Besides addressing the impending crisis for small retailers, they could target for elimination some of the many tax exemptions that contribute to the system’s complexity, even if it requires going to voters.

With Democrats poised to take control of state government there is much talk about bold reform. Well, that’s exactly what this state’s mind-boggling sales-tax system so desperately needs.