Sales-tax compliance is a persistent source of client confusion for accounting firms. It appears in questions about state notices, audit preparation, and growing ecommerce businesses that discover they have been filing in the wrong states.
Here are the structural reasons it trips up clients and the steps firms can take to help.
Dealing with Fragmented Rules
Sales tax has no single nationwide authority. Clients must manage:
- 50 different sets of state rules.
- Hundreds of local jurisdictions.
- Product taxability that changes by product, buyer location, and delivery method.
- Rules that can treat the same product differently across states.
A software subscription may be taxable in one state and exempt in another. Groceries, clothing, digital goods, and SaaS products can all have different treatments. This fragmentation is a structural feature of sales tax.
Wayfair Changed Everything, and Clients Haven’t Caught Up
Before the 2018 South Dakota v. Wayfair decision, sales-tax obligations were largely tied to physical presence. Economic nexus now means that crossing a state’s revenue or transaction threshold can create a compliance obligation even without a physical footprint.
Firms should include sales-tax exposure in client onboarding and recurring reviews, especially for clients with multi-state or ecommerce sales.
Marketplace Complexity Adds Another Layer
Many clients sell through multiple channels, such as a direct Shopify storefront, Amazon, or Faire. Marketplace facilitator laws shift collection and remittance responsibilities for covered sales to the platform, but clients still have different obligations for different channels.
Reconciliation typically requires tracking what was collected through each channel, what is owed by jurisdiction, and what was remitted on the client’s behalf. Without good tooling, this can consume significant staff time.
Automating Sales Tax
Firms that build a sales-tax offering tend to separate rules-based, high-volume work from advisory work.
What Gets Automated
- Nexus monitoring.
- Registration and renewals.
- Filing and remittance.
- Reconciliation.
What Staff Focuses On
- Interpreting ambiguous situations.
- Advising on voluntary disclosure.
- Guiding clients through audits.
- Strategic compliance planning.
This division can make sales-tax advisory more scalable by reducing the manual workload added by each new client.
A Practical Starting Point
Firms that have not formalized a sales-tax offering can start by:
- Conducting nexus reviews for existing clients with multi-state sales.
- Adding sales-tax exposure questions to new-client intake.
- Identifying a compliance platform that can handle operational work.
Firms that already offer this service should ask whether their current approach can serve more clients without adding proportional headcount.
Sales tax is unlikely to become simpler. Firms that build a repeatable capability can give clients a clearer way to manage notices, registrations, filings, and growth across jurisdictions.
Kintsugi shares practical guidance on sales-tax automation and can help firms evaluate workflows for their clients.
