You’re growing across states. Sales tax shouldn’t slow you down.

Physical nexus arises from tangible presence in a state. For example, having employees, inventory, or property in the state typically creates nexus. Even out-of-state companies can establish physical nexus by storing goods in a fulfillment center (like Amazon FBA) or by employees working there. Once physical nexus exists, the business must collect and remit that state’s sales tax on taxable sales to customers in that state.

Economic nexus is based on sales volume. Many states follow the Wayfair model: grossing over $100,000 in sales or 200 transactions in the state within a period. However, each state can set its own rules – some use only taxable sales amounts, some include resale sales, and some use a rolling 12-month window. When your sales exceed a state’s economic threshold, you are required to register for that state’s sales tax and begin collecting tax on applicable sales.

As soon as you determine that nexus is met (physically or economically), you must register for a sales tax permit in that state before you collect tax. Registration usually involves applying for a Certificate of Authority or Sales Tax Permit via the state’s tax portal. For example, in Massachusetts you use MassTaxConnect to get a Sales Tax Certificate of Authority. After registration, you can legally collect sales tax and file returns. (Until registration is complete, you may need to accrue tax and file a return once approved.)

Once registered, you must charge the correct tax rate on each sale. This means configuring your e-commerce or invoicing system with the state’s sales tax rates and rules. Rates vary by jurisdiction and product type. It’s best practice to use a reliable tax calculation system (e.g. Avalara, TaxJar, or Stripe Tax) that keeps rates up-to-date. You should also map which products or services are taxable in each state and handle local levies (counties, cities) appropriately. Periodically reconciling collected tax against what should have been collected helps catch errors before filing.

Filing frequency (monthly/quarterly) depends on each state’s rules and your sales volume. Some states require monthly returns if you collect above certain amounts; others allow quarterly or annual filings. Each state and locality has its own due dates and payment methods. For example, you might file monthly in one state and quarterly in another. Keeping a consolidated filing calendar is crucial. Our service maintains a Filing Calendar and archives each return to ensure on-time compliance in every jurisdiction.

Maintain detailed records of all sales, tax collected, and remitted. Keep copies of sales tax returns, payment confirmations, and exemption (resale) certificates. You should track sales by jurisdiction (state/county/city) and maintain backup invoices. In case of audit, you’ll need an audit trail showing what tax was charged or why it wasn’t (i.e. valid exemption certificates). Organized records help demonstrate compliance and simplify any future reviews or audits.

A resale or exemption certificate allows a purchase to be made tax-free when the buyer resells the item or is otherwise exempt. For example, wholesalers purchase inventory tax-free by providing a resale certificate. Nonprofits or certain organizations may also be exempt and provide certificates. You must collect a valid certificate at the time of sale for any exempt transaction. Without it, the sale is presumed taxable.

Effective certificate management means collecting, validating, and storing certificates securely. You should obtain a certificate for each exempt customer and document their exemption status. Certificates expire or change, so track expiration dates and renew as needed. Automation tools can help manage certificates, but the key is having a process: for example, a central repository (like a secure cloud folder) and periodic certificate audits. Our service sets up such a process so certificates are current and easily retrievable for each state.

If a state audits you, they will examine your sales to ensure tax was correctly collected or exempted. Auditors often use sampling rather than checking every transaction. This means if a sample shows missing tax (e.g. a missing certificate), they may apply that finding more broadly. Therefore, you need complete documentation for exempt sales. Having exemption certificates on file for audited transactions can prevent a tax liability during an audit. Our audit support means we help gather documents, respond to notices, and explain any discrepancies with the tax agency.

Yes. Most states now have marketplace facilitator laws. These laws make platforms like Amazon or eBay responsible for collecting and remitting sales tax on behalf of third-party sellers. If you sell through such marketplaces, you may not need to collect tax on those sales yourself (the marketplace will do it). However, you should confirm which marketplace sales are covered and ensure you don’t inadvertently collect tax twice. (Meanwhile, sales you make directly on your own site still require normal nexus and collection logic.)

State and local sales tax laws change frequently (new rates, thresholds, products). To stay compliant, you must monitor changes in every state where you have nexus. Using a sales tax automation tool (TaxJar, Avalara) can help by automatically updating rates and flags for nexus. Alternatively, a managed service will handle this: we continuously review your footprint (sales, inventory, employees) and track legislative changes so your compliance map is always current.

Common errors include: failing to register after nexus is hit, charging incorrect rates (often forgetting local taxes), filing late or in the wrong frequency, and not obtaining exemption certificates for tax-free sales. For example, many sellers overlook economic nexus thresholds and start selling tax-free until faced with back taxes. Another pitfall is not tracking remote employees or inventory locations, which can unexpectedly create nexus. Our process is designed to catch these issues: we perform a thorough Nexus Assessment, ensure correct rate configuration, and implement controls (like certificate collection) to prevent such mistakes.

Automation can greatly simplify compliance. Tax engines (Avalara, TaxJar, Sovos, etc.) can calculate taxes in real-time and manage filing workflows. For instance, TaxJar’s blog emphasizes that automation “helps you understand and determine if you have exceeded any nexus thresholds”. However, tools must be configured correctly and paired with human oversight. We often integrate automation for tasks like tax calculation and filing reminders, while our team ensures the system’s data and rules are accurate. This hybrid approach scales with your business growth.

A managed sales tax service brings expertise and consistency. Multistate compliance is complex; a mistake can cost penalties and interest. With a service like Crownglobe’s, you get a repeatable process: we map your nexus exposure, register in required states, set up a filing calendar, and maintain all documentation (returns, certificates) in one place. This clarity and control reduce audit risk and free you to focus on growth, knowing that your sales tax obligations (nexus determination, filings, exemptions) are handled professionally.