Kintsugi Sales Tax Integration: Setup and Sync
Connect Kintsugi, a sales tax automation provider, to DualEntry to calculate sales tax in real time, monitor economic nexus, and prepare returns across the jurisdictions where you sell. DualEntry reaches Kintsugi through Apideck, a unified API platform, so the connection is brokered and authorized by Apideck rather than through a direct credential exchange with Kintsugi. Reference data and tax results flow into DualEntry; Kintsugi remains the system of record for your tax compliance data.
Prerequisites
Confirm the following before connecting:
- An active Kintsugi account with sales tax calculation enabled for the jurisdictions where you have nexus.
- Authorization to connect Kintsugi through Apideck. DualEntry uses Apideck Vault to store the connection credential and manage its token lifecycle, so you complete a short authorization flow instead of pasting a raw API key into DualEntry.
- The companies (legal entities) you tax exist in DualEntry with complete addresses. Address precision drives jurisdiction selection, so each entity needs a full ship-from address.
- Your customers and items carry the tax attributes Kintsugi needs: a taxable or exempt status on each customer, and a product tax category on any item taxed at a non-standard rate.
You do not need a separate Apideck account. The Apideck connection is managed by DualEntry, and you authorize Kintsugi through the Apideck Vault flow that DualEntry opens during setup. If your organization already uses Kintsugi outside DualEntry, the same Kintsugi account is the one you authorize here.
How the Apideck connection works
DualEntry does not call Kintsugi directly. It calls Apideck’s unified Accounting API, and Apideck translates each request into Kintsugi’s own API. This unified-API model means DualEntry speaks one consistent interface while Apideck maintains the Kintsugi connector behind it.
Three pieces make up the connection:
- The unified API. DualEntry sends tax calculation and reference requests to Apideck in a single normalized shape. Apideck maps each field to Kintsugi’s equivalent, so you never configure Kintsugi’s raw endpoints inside DualEntry. Apideck’s accounting coverage lists the connectors this API supports.
- Apideck Vault. Vault holds the Kintsugi authorization for your organization and manages OAuth flows, API keys, and token refresh. You authorize once, and Vault keeps the connection live.
- Webhooks. Apideck forwards Kintsugi events, such as a tax rate change in a jurisdiction you sell into, so DualEntry reacts without polling.
Because the connection is brokered, the provider behind it can change without changing how DualEntry calls it. Kintsugi is the active sales tax connector; the same Apideck model backs other accounting and ERP connectors in Apideck’s catalog.
Apideck Vault stores and refreshes the Kintsugi credential on DualEntry’s behalf. You authorize the connection once during setup; you do not paste or rotate a Kintsugi API key inside DualEntry.
Connect the integration
Authorize the Kintsugi connection through Apideck, then let DualEntry pull the reference data it needs to tax transactions.
- Navigate to Settings → Integrations → Kintsugi.
- Choose Connect. DualEntry opens the Apideck Vault authorization flow for Kintsugi.
- Sign in to Kintsugi, or provide your Kintsugi API key, in the Vault dialog and approve access. Vault stores the credential and returns you to DualEntry.
- DualEntry confirms the connection with a test call to Kintsugi through Apideck. A successful check marks the integration Connected.
After the connection is live, DualEntry pulls Kintsugi reference data: the jurisdictions where you are registered (your nexus footprint) and the product tax categories available for taxability mapping. This reference data refreshes on demand and when Apideck delivers a relevant webhook, so you do not maintain it by hand.
Map entities and tax settings
Before tax calculates on transactions, align DualEntry’s companies and tax attributes with Kintsugi so each sale is taxed under the right registration and at the right rate.
- Companies. Map each DualEntry company to the matching Kintsugi entity so transactions are taxed under the correct registration. A company with no mapping cannot be taxed through Kintsugi.
- Nexus. Kintsugi monitors economic nexus and tells you where you are approaching or have crossed a registration threshold. DualEntry imports the jurisdictions where you are already registered and uses them to decide which sales to tax.
- Customer taxability. Mark each customer Taxable or Tax Exempt. Exempt customers should carry the exemption documentation Kintsugi expects so exempt sales are reported correctly.
- Product tax categories. Assign a Kintsugi product tax category to items taxed at a non-standard rate. Items without a category use Kintsugi’s default taxable treatment.
What Kintsugi handles
Kintsugi owns the sales tax compliance workflow; DualEntry owns the ledger and the transactions that feed it. Knowing the split clarifies where each task happens.
- Real-time calculation. Kintsugi returns the tax rate and amount for each taxable transaction based on the customer’s ship-to address and the item’s tax category. DualEntry posts that amount as a tax line on the source document.
- Nexus monitoring. Kintsugi tracks your sales by jurisdiction and flags where economic nexus thresholds are met, so you know where to register.
- Registration, filing, and remittance. Kintsugi handles jurisdiction registration and prepares and files returns. DualEntry provides the transaction data that supports those filings.
- Exemption certificates. Kintsugi stores and validates exemption certificates. DualEntry marks the customer exempt so the calculation skips tax.
DualEntry retains its own native tax engine and an Avalara integration as alternatives. Kintsugi focuses on US sales and use tax; for EU/UK VAT and GST, use DualEntry’s native multi-jurisdiction engine.
What syncs
The integration moves reference data one way and calls Kintsugi in real time for tax calculation, all through Apideck. The table below lists each flow.
| Kintsugi data (via Apideck) | DualEntry record | Direction | Frequency |
|---|
| Registered jurisdictions (nexus) | Nexus reference | Kintsugi → DualEntry | On connect and on change |
| Product tax categories | Item tax category options | Kintsugi → DualEntry | On-demand |
| Tax calculation | Tax line on transaction | DualEntry → Apideck → Kintsugi → DualEntry | Real time during transaction entry |
| Tax rate changes | Updated rate reference | Kintsugi → Apideck → DualEntry | Webhook |
invoice, sales_order, cash_sale, and customer_credit. The customer’s shipping address determines the jurisdiction, falling back to the billing address when no ship-to address is present.
Current limitations
A few aspects of the integration are worth knowing before you rely on it:
- US sales tax focus. Kintsugi calculates US sales and use tax. For EU/UK VAT and GST, use DualEntry’s native tax engine rather than Kintsugi.
- Brokered connection. Connection health depends on the Apideck Vault authorization. If the Apideck connection drops or its token cannot refresh, tax calculation fails until you reauthorize.
- Complete addresses required. Real-time calculation needs a full ship-to address on the customer or transaction. Incomplete addresses produce inaccurate or failed calculations.
- One-way reference sync. DualEntry does not push companies, customers, or items into Kintsugi. Configure each system’s master data independently.
- Reference updates are not retroactive. A nexus or rate change that Apideck delivers by webhook applies to transactions you post after it arrives. It does not recalculate tax on already-posted transactions, so review historical entries separately when a rate changes.
Troubleshoot tax calculation errors
When tax does not appear on a transaction or Kintsugi returns an error, the most common causes are below.
| Symptom | Cause | Resolution |
|---|
| Integration shows disconnected | The Apideck Vault authorization expired or was revoked. | Reconnect under Settings → Integrations → Kintsugi to re-run the Vault authorization. |
| Company cannot be taxed | The DualEntry company has no Kintsugi entity mapping. | Map the company to its Kintsugi entity, then retry the transaction. |
| Tax not applied for a state | You have no registered nexus in the customer’s jurisdiction. | Register in Kintsugi for that jurisdiction; the nexus reference refreshes into DualEntry. |
| Tax amount looks wrong | The item has no product tax category, or the customer address is incomplete. | Assign the correct product tax category and complete the ship-to address, then recalculate. |
| Exempt customer still taxed | The customer is not marked Tax Exempt in DualEntry. | Set the customer to Tax Exempt and attach the exemption documentation Kintsugi expects. |
Result
After completing these steps, sales tax is calculated automatically on every invoice, sales order, cash sale, and customer credit you post in DualEntry, with Kintsugi monitoring nexus and preparing your filings behind the scenes through Apideck. To compare alternatives, see the Avalara AvaTax integration and DualEntry’s native Tax Management. To configure the customer and item records that feed tax calculation, see Accounts Receivable. To connect more systems, return to Integrations.