TL;DR

• Your historical filing data exports from Avalara and stays audit-ready. You leave with full records, not a gap.

• Open returns finish on Avalara. You switch between filing periods, never mid-return.

• A complete migration runs four to eight weeks. Levanta switched and recovered $13K+ in over-collected tax within that window.

• Compliance never lapses. A short parallel-run overlap keeps both systems live until your first clean filing confirms the handoff.

Why Finance Teams Stay on Avalara Too Long

Most finance teams stay on Avalara long past the point of frustration because switching feels riskier than enduring the problem. The fear is concrete. You worry about losing historical returns, missing a filing deadline during the cutover, or breaking an ERP integration mid-quarter. So the renewal auto-renews, and another year passes.

The decision usually forces itself. A renewal notice lands, an audit exposes a gap, or someone finally checks the numbers. Levanta's VP of Finance, Jinal Sanghavi, found Avalara over-remitting sales tax by two to three times the correct amount, processed automatically without her approval. Avalara never flagged it. She caught it by digging into the figures herself.

That story reframes the actual risk. Staying on a platform that moves money without your sign-off carries compliance exposure you cannot see until it costs you. A planned migration, by contrast, happens on your schedule with full visibility into every return. Leaving is the lower-risk move, and the rest of this guide shows how to execute it without missing a filing.

What You're Actually Moving: A Migration Inventory

A migration off Avalara moves four distinct asset classes, and naming them upfront turns a vague worry into a scoped project. Once you know what you have, the work stops feeling like a leap and starts looking like a checklist. The four are your historical returns, your nexus registrations, your exemption certificates, and your ERP or billing integrations.

Your historical returns are every filing Avalara has submitted on your behalf, plus the supporting transaction detail behind them. You need these accessible and audit-ready well after the account closes, because a state can examine a prior period years later. Export them in a format that stands on its own rather than one that lives inside Avalara's interface.

Your nexus registrations are the state-level accounts that establish where you collect and remit. These belong to you, not to Avalara. The registration numbers, filing frequencies, and login credentials transfer to your new platform without re-registering, so this asset class is usually lighter work than people expect.

Your exemption certificates are the documents that justify not charging tax on specific customers. If you sell to resellers, nonprofits, or government buyers, these certificates protect you in an audit, and a gap here creates real liability. Export the full certificate library with expiration dates intact so your new platform can manage renewals without a lapse.

Your ERP and billing integrations are the connections feeding transaction data into the tax engine, whether through NetSuite, Stripe, Shopify, or a custom billing system. Mapping which systems push data and how is the most technical part of the inventory, and it determines how much of the project your new provider handles versus what your team owns. Document each connection before you start, and the rest of the migration follows a known path.

When to Switch: Timing the Migration to Your Filing Calendar

The cleanest moment to migrate is right after you file, not while a return sits open. Pick the window that starts the day after a filing deadline or, better still, the first week after quarter-close. At that point Avalara has remitted everything due for the period, your books reflect what went out, and the new platform takes over a clean slate rather than a half-finished obligation.

Migrating mid-period invites the one error finance teams fear most, a return that falls between two systems and never gets filed. If you switch on June 18 with a July 20 deadline, you now have to decide which platform owns June. Splitting a single filing period across two providers creates reconciliation work and a real chance of a missed return. Wait until the period closes and the ownership question answers itself. The old system filed the last period, the new one files the next.

Most teams run both systems at once for a few weeks, and that overlap is the design, not a stumble. You keep Avalara active through the final period it owns while the new platform handles registrations, integrations, and validation in parallel. During that stretch you pay for two tools briefly, which feels wasteful until you compare it to the cost of a gap in coverage. The overlap is the insurance that nothing slips.

A practical rule for the calendar maps to how you file. If you file monthly, target the first week of a new month. If you file quarterly, target the week after a quarter-close, which gives the new platform a full quarter to onboard before its first live filing. Either way, the goal is the same. Your last Avalara filing and your first filing on the new platform belong to different periods, with no overlap on any single return.

The Migration Checklist: Step-by-Step

Run this checklist in order. Each step depends on the one before it, and skipping ahead is where migrations go wrong.

1. Export your full Avalara data set. Pull every filed return, your transaction-level liability detail, nexus registrations by state, and your exemption certificate library. Save these in a format you can open without an Avalara login, because your access ends when the contract does. Do this first so you know exactly what you have before you commit to a switch date.

2. Reconcile the export against your own records. Match Avalara's filed amounts to your ERP or billing data for the trailing four quarters. Levanta found Avalara had been over-remitting by two to three times the correct amount, a gap nobody caught until VP of Finance Jinal Sanghavi reconciled the numbers herself. This step surfaces over-collection, under-collection, and any prior-period exposure before a new platform inherits it.

3. Confirm your switch window. Pick a date after a filing deadline, never mid-period on an open return. Map which returns Avalara still owns through the cutover and which the new platform picks up. Write this date down and share it with everyone touching the project.

4. Stand up the new platform's integrations. Connect your billing system, ERP, and tax calculation engine. Confirm nexus registrations carry over and that your exemption certificates load correctly. With Taxwire, this is the part the onboarding team handles directly. You provide the export and credentials, and Taxwire configures the connections.

5. Run both systems in parallel for one filing period. Keep Avalara active and calculate the same period on the new platform without filing from it yet. Compare the two outputs line by line. Matching numbers tell you the new system reads your transaction data correctly. A parallel run is standard practice, not a sign something went wrong.

6. File your first live return on the new platform. Once the parallel period reconciles cleanly, file the next period entirely on the new system. With Taxwire's managed model, every filing is customer-approved before submission, so nothing moves without your sign-off. You own the approval. Taxwire prepares the return and handles the remittance once you green-light it.

7. Confirm the first filing posted correctly. Verify each state received the return and the payment cleared for the right amount. Check confirmation numbers against your filing calendar. This is the milestone that proves the migration worked, not the integration going live.

8. Close the Avalara account on your terms. Only cancel after one full filing cycle has run clean on the new platform and you have archived your historical data. Time the cancellation to your contract renewal so you are not paying for two systems longer than the overlap requires.

The division of labor matters here. Taxwire's onboarding covers the configuration, integration, and filing preparation. You own the data export, the reconciliation decisions, and the final approval on every return. That split keeps you in control of compliance while removing the manual setup work that makes Controllers dread a migration.

Historical Data and Back-Tax Exposure: What to Do Before You Close the Account

Export your full Avalara filing history before you cancel the account, because access disappears when the contract ends. Avalara lets you download filed returns, transaction reports, and remittance records, and you should pull all three rather than just the summary returns. Save them as PDFs of the actual filed documents plus the underlying transaction data in CSV. An auditor wants to see the return you filed and the transactions that produced each number, so a summary report alone will not hold up under examination.

Archive those files somewhere outside the platform you are leaving and outside the platform you are joining. A shared drive or document management system with dated folders by jurisdiction and period works fine. The goal is that three years from now, when a state opens an audit on a period you filed through Avalara, you can produce the return and its supporting records without logging into a tool you no longer pay for. States can look back three to four years on sales tax, so the records need to outlive the vendor relationship by a wide margin.

A migration is the right moment to surface prior-period exposure, because you are already pulling every transaction and reviewing every registration. Look for two things. First, jurisdictions where you crossed an economic nexus threshold but never registered, which means you owe tax you never collected or remitted. Second, periods where Avalara mishandled the math. Levanta found Avalara had been over-remitting by two to three times the correct amount and recovered more than $13,000 once they switched, an error their VP of Finance caught only by digging into the numbers herself.

Resolve any liability you find before your new platform inherits the position. Unregistered nexus often resolves through a voluntary disclosure agreement, which caps the lookback period and waives penalties in most states. Handling that during migration is far cheaper than letting a state find it later. A clean baseline also means your new platform starts with accurate registrations and no hidden gaps carried forward from the old one.

How Long a Compliant Migration Actually Takes

A complete migration runs four to eight weeks for most companies in the $10M to $250M range, but two milestones inside that window get confused. Setup is the first one. Registrations transfer, integrations connect to your ERP and billing system, and exemption certificates load into the new platform. The first live filing is the second milestone, and it lands one filing cycle after setup finishes, not the day your account goes live.

Treating these as one event is where teams panic. Taxwire's setup takes one week. Your first live filing lands one full filing cycle after that, because filing happens on the state's calendar, not yours. Your registrations can be active and your data fully imported while your first return is still weeks out. A platform that promises a one-day cutover is either hiding the setup work or skipping the parallel run that protects your first filing.

Levanta, an affiliate platform pacing toward $286M in annualized GMV, recovered more than $13K in sales tax that Avalara had over-collected within weeks of switching to Taxwire. That timeline reflects one scaling SaaS company with clean nexus data, not a guarantee for every account. Read it as evidence that a careful migration recovers money and closes control gaps fast, rather than a fixed number to plan your own switch around.

Taxwire's Managed Migration Handoff

Taxwire fixes the exact control gap that pushed you off Avalara. Avalara processed Levanta's payments automatically, remitting 2 to 3 times the correct amount with no sign-off, and Jinal Sanghavi, the VP of Finance, only caught it when she dug into the numbers herself. Taxwire requires your approval before anything moves. Nothing files, nothing remits, and nothing leaves your account without your green light.

That approval model also reshapes the migration itself. A managed handoff means Taxwire's team scopes your historical returns, nexus registrations, exemption certificates, and integrations, and you confirm each step rather than discovering errors after the fact. Levanta recovered more than $13K in overpaid tax within weeks of switching, and the disruption finance teams fear never materialized.

If your Avalara contract renews soon or a failed audit made the decision final, the next move is a short conversation. Taxwire implements in one week and runs the parallel-filing period with you, so your first live return on the new platform is clean and verified before you close the old account.

Talk to Taxwire about your migration and we will map your filing calendar, scope your data, and set your first compliant filing date.

FAQs

What happens to open returns if I switch mid-quarter? An open return stays the responsibility of whichever platform was collecting and filing for that period. Taxwire times the cutover so Avalara files the period it already tracked, and Taxwire takes over from the next clean period. The practical benefit is that no filing falls through the gap between two systems.

Can I export all my historical filing data from Avalara before I leave? Avalara lets you export filed returns, transaction detail, and remittance records before your account closes. Taxwire helps you pull and archive that data in an audit-ready format during onboarding, so a state inquiry years later still has a complete trail. Export everything while the account is active, because access ends when the contract does.

Do I need to re-register for sales tax in states where I'm already registered? No. Your state sales tax registrations belong to your company, not to Avalara, so they carry over unchanged. Taxwire connects to your existing registrations and begins filing under the same account numbers, which means you skip the weeks of re-registration paperwork a new entity would face.

What if a migration uncovers back-tax exposure I didn't know about? A migration audit often surfaces prior-period exposure that the old platform never flagged, the way Levanta found Avalara had over-collected by 2 to 3 times. Taxwire identifies the liability before the new platform inherits it and helps you address it through a voluntary disclosure or correction. Catching exposure during the switch costs far less than letting an auditor find it first.

How do I handle the overlap period if my Avalara contract hasn't expired yet? Run both platforms in parallel until your Avalara term ends, with Taxwire configured and validated in the background. The overlap is a normal part of a clean migration, and it lets you confirm the first Taxwire filing is correct before you cancel Avalara.