Five Ways to Track Sales Tax Nexus, Compared Honestly
Reviewed for 2026, updated September 8, 2026.
From a hand-built spreadsheet to a fully outsourced compliance stack, here is how the common approaches to nexus tracking hold up on cost, accuracy, effort, scale, and control.
Every seller who crosses into a second or third state eventually has to answer the same question: who or what is watching the thresholds, and who is making sure the returns go out on time? There is no single right answer. A two-person shop selling in four states has different needs than a warehouse operation shipping into forty. What follows is our honest read on the five approaches we see most often, including the one we build. We have tried to describe each one the way we would to a friend, with the weaknesses stated plainly. Cost figures are deliberately left as ranges and relative comparisons, because pricing changes and your situation determines what any option actually costs you.
| Option | Upfront and ongoing cost | Threshold accuracy | Time required each month | Scalability across states and channels | Visibility and control |
|---|---|---|---|---|---|
| Manual spreadsheet trackingBest for: Sellers in a handful of states with one or two sales channels and a disciplined bookkeeper who will actually update it. | Essentially free in dollars. The real cost is the bookkeeper's time and the risk of a stale cell. | Only as good as the last update and the person's understanding of what each state counts. Easy to get right in three states, easy to drift in ten. | A few hours to export sales by state, update totals, and eyeball the thresholds, more if data lives in several systems. | Poor past roughly a dozen states or more than two channels. Rolling twelve month windows and per-state counting rules are hard to maintain by hand. | Total control and total transparency, as long as the person who built it is still around and the formulas are documented. |
| Nexus monitoring software with filing remindersBest for: Growing sellers who want early warning on thresholds and deadlines but are comfortable filing returns themselves or through a bookkeeper. | A modest monthly subscription, typically far less than an accountant's retainer or a full automation platform, with little to no setup cost. | Good when sales channels are connected and state rules are kept current by the vendor. Still depends on you confirming taxability of your products in each state. | Minutes to review alerts and a filing calendar, plus the time to actually prepare and file returns, which the tool does not do for you. | Handles many states and multiple channels well. The bottleneck becomes the filing work itself, not the tracking. | High. You see every state's progress toward its threshold and every due date, and you decide what to do about each one. |
| Accountant or CPA managed complianceBest for: Businesses with complex taxability questions, past exposure to clean up, or no internal capacity to own the process at all. | The most expensive option per state on an ongoing basis, usually billed as a retainer or per return, with additional fees for projects like voluntary disclosure. | Depends heavily on the firm's sales tax specialization and on you delivering clean sales data by state every period. Many general accountants do not track nexus proactively. | Low for you once the data handoff is routine, but the handoff itself still requires someone in the business to produce accurate exports. | Scales fine in expertise, but cost grows roughly with the number of returns, and turnaround can slow during busy season. | Moderate. You get judgment and accountability, but you may not see threshold status unless you ask, and you are dependent on their responsiveness. |
| Full-service automated compliance platformBest for: High-volume sellers in many states who want calculation, registration, filing, and remittance handled end to end and can absorb the cost. | Highest total cost, often combining a platform fee, per-return charges, per-transaction calculation fees, and onboarding work to connect every system. | Strong when every sales channel is integrated. Gaps appear when a channel is left out or product tax codes are mapped incorrectly at setup. | Lowest once running. The recurring work shifts to reconciling the platform's filings against your books and reviewing exceptions. | Excellent. Designed for dozens of states and many channels, and it absorbs new registrations with little added effort. | Lower. Much of the process happens inside the platform, and errors in tax code mapping or sourcing can persist unnoticed if nobody reviews the output. |
| Marketplace-only relianceBest for: Sellers whose every sale flows through marketplaces that collect and remit on their behalf, with no direct website, wholesale, or invoice sales at all. | No direct cost, since the marketplace collects and remits as the facilitator. | Misleading. Many states still count marketplace sales toward your own economic nexus threshold, and inventory in a fulfillment warehouse can create physical nexus regardless of who collects. | Almost none, which is exactly why problems go unnoticed until a direct channel is added or a state sends a questionnaire. | Breaks the moment you add a single non-marketplace channel, because you may already have nexus in states where you now need to register and collect yourself. | Very low. You are trusting the marketplace's compliance and have little insight into your own standing in each state. |
- Manual spreadsheet tracking: This is where almost everyone starts, and for a small seller it is genuinely fine until it quietly stops being updated.
- Nexus monitoring software with filing reminders: This is the category ShopTaxie sits in, so weigh our view accordingly. The honest limitation is that it tells you what to do and when, but it does not file for you.
- Accountant or CPA managed compliance: Best paired with your own tracking. A professional who receives good data does great work, and one who receives nothing at all can only react.
- Full-service automated compliance platform: Powerful, but automation is not the same as correctness. Someone still needs to check that what was filed matches what was sold.
- Marketplace-only reliance: Reasonable as a starting point for a pure marketplace seller, but it should come with a plan for what happens the day you open a direct channel.
Our verdict
For most small and mid-sized sellers, the practical answer is layered rather than singular. A spreadsheet or a monitoring tool watches the thresholds and the calendar. A bookkeeper or the founder files the routine returns. A sales tax professional is brought in for the specific moments that need judgment: product taxability in a new state, a voluntary disclosure, an audit, or the first-time setup of a full automation platform when volume justifies it. Sellers who try to make one option do everything tend to either overspend on automation they do not yet need or underspend on a spreadsheet that has quietly stopped reflecting reality.
If we had to give a single rule, it would be this: choose the approach that guarantees someone will actually look at your state-by-state sales every month. A free spreadsheet that gets updated beats an expensive platform nobody reconciles. Our own product exists for the sellers in between, who have outgrown the spreadsheet but are not ready for a full compliance stack, and we think that is a large and underserved group. But whichever option you pick, pair it with a named owner inside the business and a habit of monthly review. That combination catches more problems than any individual tool.
Frequently asked questions
Can I combine nexus monitoring software with an accountant?
Yes, and this is one of the most common and effective setups. The software watches thresholds and deadlines across all your channels, and you share its state-by-state report with your accountant so they can handle registrations, taxability questions, and any cleanup work. The accountant gets clean data and you get professional judgment where it matters.
When does a spreadsheet stop being enough for nexus tracking?
The usual signals are more than a handful of states in play, more than one or two sales channels, states with rolling twelve month measurement windows, or a bookkeeper who has missed an update more than once. If any of those describe you, the risk of a silent error has probably outgrown the savings of doing it by hand.
Read the complete guide for the full reasoning behind this comparison.