WooCommerce 11.3 beta changes how a logged-in customer's session survives an account save. An exemption should not disappear merely because checkout saved an address. Equally, custom code must not leave the customer exempt after the information used to grant that exemption has changed.
These are technical state-management checks for the beta available October 28, 2026. They do not determine who legally qualifies for a tax exemption. Use the store's approved tax rules and a sandbox payment method on staging.
Name the two failures before testing
The customer-session fix preserves VAT exemption and calculated-shipping session values for the same customer when saved account data changes. Addresses can still refresh from the account. The intended distinction is between persisted account information and session-only state.
A persistence failure means an otherwise eligible buyer unexpectedly sees tax after an account save or declined payment. A revocation failure means a buyer remains exempt after the conditions supporting the exemption no longer hold. Testing only the happy path can miss the second failure.
Do not add a snippet that marks every logged-in customer exempt. That would replace the business rule rather than test it. Use your tax integration's supported sandbox fixtures or ask its developer for a narrowly scoped test case.
Prepare four observations, not one screenshot
Record the current eligibility decision, exemption flag, displayed checkout tax and final saved order tax. Use invented customer data. Keep the currency, cart and tax-display settings constant while changing the one condition being investigated.
| Step |
Change |
Question |
| Initial checkout |
Eligible test buyer |
Is the starting decision correct? |
| Account save |
Save permitted account details |
Does the decision survive appropriately? |
| Payment retry |
Deliberate sandbox decline |
Does tax unexpectedly reappear? |
| Eligibility transition |
Change the approved test input |
Does the integration recompute and clear the flag? |
Test persistence and revocation separately. A flag that survives a save must still change when eligibility changes.
Reproduce the declined-payment path
Use the gateway vendor's documented test mode and a test case that returns a decline. Make sure the cloned site cannot send real fulfillment requests or customer emails. A staging domain alone does not make a live gateway safe.
Log in as the test customer, open checkout, and record the total. Save an address change that should not alter the approved eligibility decision. Submit the sandbox payment, observe the decline, then return to checkout using the same session. Compare the tax line before and after.
Repeat with the checkout implementation the store actually uses. If it supports both block and classic checkout, run separate cases rather than assuming a result from one covers the other. Also check an account edit made outside checkout when that is part of the customer journey.
Audit code that only sets true
Search custom plugins and integration code for set_is_vat_exempt. Trace where the decision is made, what inputs it uses and which events rerun that decision. A callback that only ever sets true needs scrutiny. It should explicitly apply the current boolean result, not rely on an unrelated account save to reset state.
Do not clear the flag globally on every request as a workaround. That can recreate the original problem for valid customers. Fix the decision boundary and verify both directions with the same fixture.
After checkout succeeds in the sandbox, use the order and email reconciliation guide to compare order, gateway, invoice and email totals. Session correctness is necessary but does not prove every downstream document is correct.
Escalate with the build, checkout type, integration version and the exact transition that changes the tax incorrectly. Redact VAT numbers and addresses. A targeted checkout investigation should trace the decision, not replace your tax policy.
Sources checked October 28, 2026. Synthetic fixtures and diagrams illustrate the proposed checks; they are not claims of customer testing.