Once Avalara AvaTax is connected to LASSO, sales tax calculates automatically on your quotes and invoices, and committed invoices post straight into Avalara. Getting there takes three things: a live connection, revenue types mapped to Avalara tax codes, and addresses Avalara can pin on a map. Miss any one of them and your sales tax comes back as zero.
This article walks through the full setup in order, then covers the issues customers run into most often.
Before You Start
You will need the following from your Avalara account:
Your Avalara Account ID
A generated License Key
Your Company Code
You will also need LASSO Administration access, since the Avalara settings and tax code mappings live in Company Settings.
Step 1: Connect Your Avalara Account
In LASSO, go to Administration, then scroll down to Company Inventory/Quote Settings.
Open the Avalara section.
Enter your Account ID, License Key, and Company Code.
Save your changes, then run Test Connection.
A success banner confirms the connection is live. Keep in mind that a successful connection only means LASSO and Avalara are talking to each other — it does not mean tax will calculate yet. The next two steps are what make that happen.
Step 2: Turn Off Disable AvaTax
In the same Avalara section, look for the Disable AvaTax setting. When this is turned on, LASSO bypasses Avalara entirely and no tax is calculated, even with a healthy connection. Turn it off and save.
Heads up: This is the single most common reason a brand-new integration returns zero tax. If you were told to leave it enabled during initial setup, switch it off once your Avalara credentials are in place.
Step 3: Map Your Revenue Types to Avalara Tax Codes
Avalara needs to know what kind of revenue it is taxing. That connection is made in LASSO by mapping each revenue type to an Avalara tax code.
Go to Administration, then Company Settings, then Tax Codes.
You will see every revenue type on your account — the LASSO system defaults plus any custom ones you have created, such as Delivery Income.
Choose the Avalara tax code that applies to each revenue type. For example, a Rental revenue type commonly maps to a rental or lease tax code.
Click Save Mappings.
Every revenue type that can appear on a quote or invoice needs a mapping. If a line item uses a revenue type with no tax code behind it — Labor, for instance, when only Equipment has been mapped — the calculation fails for the whole document, not just that line.
You only map on the LASSO side. There is no matching mapping to build in Avalara. The tax code you select in LASSO is the Avalara code, and the full Avalara tax code library is available to search from within LASSO.
Your call, not ours: Which tax code belongs on which revenue type is a business and tax decision, so we can't choose them for you. If your business needs revenue broken out differently than the defaults allow, create custom revenue types and map those too.
Step 4: Validate Your Addresses
Avalara does more than read a street address — it drops a pin. Validation sets the latitude and longitude for a location so Avalara knows exactly which state, county, and local tax jurisdictions overlap that point. Without it, tax has nowhere to calculate from.
An address that is missing detail is the other frequent cause of a failed calculation. A venue saved with only a city and state will return an address value was incomplete error. Make sure your venue records carry the full street address, unit or suite, city, state, and ZIP.
To Validate an Address
Go to the Avalara configuration screen and open Address Validation.
Choose the record type you need — account addresses, venue addresses, and so on.
Use Ctrl+F or Cmd+F in your browser to find the record you are after in the list.
Click Validate.
Review the suggestions. If the correct match is at the top, click Use This Address. If the suggestions look wrong, the underlying record is probably missing part of the street address — fix the record first, then validate again.
After changing an address or a mapping, refresh the quote or invoice page so the new settings apply. You may also need to click the refresh icon next to a line item total to force a recalculation.
Do You Have to Validate Every Address?
No, and we would not recommend spending your time that way. LASSO runs a validation when an address is entered, so complete addresses generally just work. Think of manual validation as a troubleshooting tool: if a quote comes back with a tax problem, validate that address and see whether it was the cause.
The one habit worth building is checking the address when you work at a new venue for the first time, so Avalara can drop the pin correctly before you quote it.
Step 5: Test the Calculation on a Quote
Open a quote and click Edit.
Scroll to the quote block and open it with the edit pencil.
Expand the Sales Tax section.
Deselect and reselect sales tax to trigger a recalculation, then click Apply Changes.
Tax should now populate. If it comes back as zero, work back through the checklist in the troubleshooting section below — in practice it is almost always an unmapped revenue type or an incomplete address.
Step 6: Confirm the Transaction Posts to Avalara
Quotes calculate tax, but they are not committed transactions, so they will never appear in Avalara. Only an invoice posts. To confirm the integration end to end, create and publish one.
Go to the Invoices tab and choose New Invoice. Pick whichever type fits — deposit, reconciliation, or standard.
Choose a theme, then save.
Add resources to the invoice block.
Expand the gear section, select the order, and enable sales tax.
Apply changes and save.
Publish the invoice. It is now committed to Avalara.
To verify on the Avalara side, go to Transactions, then Transactions, switch to the legacy view, and filter to Month to Date. Your invoice and its calculated tax will be listed there.
Good to know: The Invoice From Quote option stays grayed out until a quote has been accepted. And if you publish a deposit invoice, expect the tax to reflect the deposit amount rather than the full order.
One Setting to Decide Early: Deposit Invoice Revenue
LASSO needs to know whether you treat deposit invoices as revenue at the time of the deposit, or defer them until the final invoice. This affects how and when tax is reported, so settle it with your accounting team before you go live rather than after.
Troubleshooting
What You See | Why It Happens | How to Fix It |
Sales tax calculates as 0.00 right after setup | Disable AvaTax is still turned on, so LASSO is bypassing Avalara. | Turn off Disable AvaTax in Company Settings and save. |
Sales tax resets to zero when you apply changes | One or more revenue types on the document have no Avalara tax code mapped. | Map every revenue type in Tax Codes, save the mappings, then refresh the quote. |
Error mentioning an incomplete address value | The venue or account address is missing the street, unit, or ZIP, so Avalara can't place the pin. | Complete the address on the record, then validate it and choose Use This Address. |
Validation suggests an address on a completely different street | Avalara is matching on partial data because the street address was never saved. | Add the full street address to the record first, then run validation again. |
Tax looks right in LASSO but nothing appears in Avalara | The document is a quote. Quotes aren't committed transactions. | Publish an invoice, then check Transactions in Avalara using the legacy view. |
Changes to mappings or addresses don't seem to take effect | The open document is still holding the previous calculation. | Refresh the page, then use the refresh icon next to the line item total. |
Your Setup Checklist
Account ID, License Key, and Company Code entered, with Test Connection passing
Disable AvaTax turned off
Every revenue type mapped to an Avalara tax code, including custom ones
Venue and account addresses complete, with new venues validated as you add them
Deposit invoice revenue treatment confirmed with your accounting team
One published invoice verified in Avalara under Transactions
Still seeing a tax calculation you can't explain? Reach out to your LASSO onboarding contact with the event or invoice number and we'll trace the error from our side.
FAQ and other Information
Question: I have my Avalara Integration set up, but I'm missing some of the invoices. What's wrong?
Answer: Avalara only displays committed transactions (Published Invoices). While an invoice is in draft status, LASSO sends it to Avalara as a temporary (uncommitted) transaction, which is why you can see activity in the log on our side but nothing lands in your Avalara account. Once the invoice is published, it becomes a committed transaction and will appear in Avalara.
Regarding Statuses and Quotes in Avalara:
Invoice statuses of Saved, Sent, and Paid have no impact on the Avalara transfer. Publishing is the trigger.
If Avalara is used on a quote, that will always be a temporary transaction, so quotes won't show in Avalara.
Voiding an invoice sends a cancelled transaction to Avalara. Creating a new revision voids the previous revision, then re-commits the new one once it publishes.