How to switch SST providers without losing coverage

Your registrations survive the switch. Under the Streamlined Sales and Use Tax Agreement your provider is an attribute of your registration rather than the registration itself, so your Streamlined Sales Tax ID, your state accounts, and your per-state registration dates all carry over. The exposure is the gap between the outgoing provider’s last return and the incoming one’s first, and it’s yours to cover.

You’re replacing the agent that performs your sales and use tax functions, not the registration underneath it. The Governing Board is explicit about where the obligation lands in between: “If you stop using a CSP, you are responsible for filing returns with each state until you have another CSP under contract.” That one sentence is the whole risk of a switch, and everything below is about closing it.

Worth saying before you plan anything: not switching is a real answer. If the periods you’d have to cover yourself, the mappings you’d have to rebuild, and the audit question further down add up to more than the move buys you, staying put is the cheaper outcome. This page is meant to be as useful for that decision as for the other one.

What changes when you switch, and what does not

Table: what changes when you switch Certified Service Provider, what persists regardless, and why. Checked August 19, 2026.

What	Persists or changes	Why
Streamlined Sales Tax ID (SSTID)	Yes	Issued to you at registration, a 9-character ID that starts with S
State sales tax accounts	Yes	Issued by each state to you, not to your provider
Per-state registration dates	Yes	The Board states the registration date cannot be changed
Filing obligation for every period	Yes	A return is expected for each period you were registered, zero-tax periods included
Prior-period liability	Yes	Neither registering nor contracting with a provider removes it
Who prepares and files the return	Changes	Your new provider files the Simplified Electronic Return in each full member state once its services begin
Who a state contacts about your returns	Changes	States go through the provider for a CSP-compensated seller
Where your data and mappings live	Changes	The part that takes real work. See below

You’re not re-registering. You’re changing who acts for you inside a registration you already hold. Handled badly, a switch doesn’t undo your registrations. It leaves unfiled periods inside them.

One qualifier on the return itself. The Simplified Electronic Return is the uniform format the full member states accept, and Tennessee, the only associate member, allows it only for remote sellers with no business location there. See what the Simplified Electronic Return covers.

How your provider is recorded, and how it gets changed

Your provider is recorded against your SSTRS account, and the Board describes the mechanism from the joining side. A seller who registers before contracting picks a provider at registration, and that provider updates the account when its services begin. Registration updates are also on the Board’s list of things you can route through a provider.

So the account is yours, the provider is a field on it, and providers write to that field. What the Board doesn’t publish is what happens when two providers are involved at once.

What the Governing Board does not publish about switching

As of August 19, 2026, the Governing Board publishes no procedure for moving a live registration from one Certified Service Provider to another.

We checked four Board properties on that date:

The registration FAQ covers updating business information, a legal name, a FEIN, and ending registrations. Nothing on changing providers.
The CSP FAQs cover contracting with a provider before and after you register. Nothing on replacing one.
The shared registrations FAQ mentions a provider four times, and the only relationship change it addresses is ending a registration.
The Board’s seller guide to ending a registration tells a seller under contract to contact its provider to cancel or end a state registration, which covers ending, not transferring.

None of that means no mechanism exists inside the registration system. It means none is published. The sequencing below is a reasoned reading of adjacent guidance, and the operational answer has to come from the two providers, in writing, before you sign anything.

When in the filing cycle to make the change

The Agreement gives you a floor rather than a date. A state’s due date can’t fall earlier than the 20th of the month following the reporting period. Each state sets its own beyond that, so you’re managing a spread of dates, not one.

Cut over at a period boundary. Change providers inside a reporting period and one return’s data splits across two systems. At a boundary, each provider files whole periods.
Let the outgoing provider file the last full period. It holds that period’s transaction data. End the contract first and the work moves to you.
Get the incoming provider’s start date in writing, per state. You file until the new contract begins, so a start date that’s vague by two weeks is two weeks of unclear ownership.
Expect the two dates not to meet. Plan for a gap and staff it, rather than discovering it after a due date.
Do not end your registrations. That’s a different action with different consequences. If you’ve received amnesty from any Streamlined member state, you lose it if you cancel your registration within 36 months of registering. See what SST amnesty covers. Changing providers and ending a registration should never be done in one motion.

Who answers for periods your previous provider filed

Where you qualify as a CSP-compensated seller, the states will generally take audits and questions about your returns and tax payments to your provider rather than to you, and on the transactions that provider processed they have to work through it instead of contacting you directly. That routing, and what the liability relief behind it does and doesn’t cover, is how audits work when you use a CSP.

What the Board doesn’t address is which provider that is when the audited period was filed by a provider you no longer use. The Board publishes no answer as of August 19, 2026. Treat it as an open question to put to both providers, not an answered one.

Three things are documented:

Your liability doesn’t transfer to anyone. Contracting with a provider doesn’t remove a filing requirement or tax liability you already had.
The provider carries its own remittance liability. Under the current CSP Operating Contract, tax a provider doesn’t remit to a Streamlined state by that state’s due date is delinquent, and the provider is liable for paying it, subject to the exceptions the contract sets out immediately after. That’s an obligation to the states, not a promise to you.
Mapping errors were always yours. Liability relief doesn’t reach a product that you or your provider classified into the wrong product category or the wrong tax rule. Those decisions follow you across a switch.

Providers describe their own audit posture differently. Sovos states that in an audit of a Model 1 CSP-compensated seller it is the first point of contact rather than the seller, and that the liability relief is not absolute.

What to take with you before the contract ends

Extract while you’re still a customer. The current CSP Operating Contract requires a provider to keep its records in the United States for at least as long as the longest statute of limitation period of any Streamlined state, and to give the Governing Board and the states access to the records of the sellers it serves. That obligation runs to the Board and the states. The contract contains no provision requiring a provider to return your data to you, checked on August 19, 2026. Portability is a matter for your commercial agreement.

What to pull, hardest to reconstruct first:

Transaction-level detail with jurisdiction assignment and tax collected, for every period the provider filed. It’s the base layer for any later audit.
Filed returns and remittance confirmations, per state per period, with SER submissions and payment references.
Product tax code and taxability mappings, in full. These carry your own liability, and rebuilding them is where switches quietly go wrong.
Exemption certificates and certificate data. Check what you hold rather than what the platform displays. Providers differ: AccurateTax prices certificate management as an optional service rather than part of the base offering, and TaxCloud says it stores and applies certificate details but doesn’t provide automated verification or renewal tracking.
State correspondence, every notice and every response filed for you.
Registration facts: SSTID, state account numbers, registration dates, and filing frequencies.
Nexus determinations and their supporting data. Without them, the new provider starts from your assertions rather than your evidence.

One scoping point affects sequencing. Sovos states that under Model 1 a seller must use Sovos for both calculation and reporting or remittance, which rules out keeping one provider for calculation while another takes over filing. Ask each side whether a split period is possible before you design one.

The switching checklist

What this page cannot tell you

It can’t give you a documented procedure, because the Governing Board doesn’t publish one. Everything above is built from what the Board publishes about adjacent situations: joining a provider, leaving one, ending a registration, and how audits reach a CSP-compensated seller. The audit question across a provider change is unresolved in the published record as of August 19, 2026, and a state may handle a transition differently from its neighbor. Where a specific state matters, ask that state. Nothing here is legal or tax advice.

It also can’t tell you whether to move. A switch that lands on a period boundary, with both start and end dates in writing and your data already out, is a manageable piece of work. One that starts mid-period, with the mapping rebuild underestimated and the audit question unasked, is the version that goes wrong. If the second description fits your situation better than the first, waiting is a legitimate answer, and so is deciding that what you have now is good enough. For the wider decision, see what each certified provider charges and the six certified provider profiles.

Sources and last checked

Last checked August 19, 2026. Every extract, with its URL and retrieval date, is cached with its URL and retrieval date`. Primary sources: the Governing Board’s page on what a Certified Service Provider is, its CSP FAQs, its guidance on filing sales and use tax returns, its registration FAQ and the shared registrations FAQ, its seller guide to ending a registration, and the CSP Operating Contract for 2025 to 2026. The provider statements above come from each provider’s own published pages.