# Production subscription locked after removing a scheduled plan change — HTTP 500 on subsequent SwapPlan

**URL:** <https://developer.squareup.com/forums/t/production-subscription-locked-after-removing-a-scheduled-plan-change-http-500-on-subsequent-swapplan/28082>\
**Category:** Questions\
**Tags:** subscriptions-api\
**Created:** [October 2, 2026, 8:31pm UTC](https://developer.squareup.com/forums/t/production-subscription-locked-after-removing-a-scheduled-plan-change-http-500-on-subsequent-swapplan/28082 "2026-10-02T20:31:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![enigma65](https://avatars.discourse-cdn.com/v4/letter/e/f19dbf/32.png) [@enigma65](https://developer.squareup.com/forums/u/enigma65)\
**Post date:** [October 2, 2026, 8:31pm UTC](https://developer.squareup.com/forums/t/production-subscription-locked-after-removing-a-scheduled-plan-change-http-500-on-subsequent-swapplan/28082/1 "2026-10-02T20:31:49Z")

</div>

We’re testing subscription billing for a SaaS web app before launch and have encountered a locked production subscription.

Here’s the sequence:

1. Registered and paid for our Basic plan at $19/month.
2. Upgraded immediately to Advanced at $34/month. Our application collected a separate prorated payment and used `SwapPlan` to schedule Advanced for the next renewal.
3. Chose to downgrade back to Basic at renewal. Our application deleted the scheduled `SWAP_PLAN` action successfully. Advanced access remains available through the paid period.
4. Selected “Keep Advanced Plan,” which calls `SwapPlan` again to restore Advanced for the next renewal. That request failed.

At **October 2, 2026, 19:57:25 UTC** , Square returned:

```auto
HTTP 500
INTERNAL_SERVER_ERROR
Subscription ID [available privately] is locked and is not billable.
Please retry or contact support.

```

`RetrieveSubscription` still reports:

```auto
status: ACTIVE
plan_variation_id: our Basic plan variation
charged_through_date: 2026-11-02

```

No new charges or refunds appeared during the downgrade or failed restoration attempt.

We reviewed [this similar case](https://developer.squareup.com/forums/t/production-subscription-is-locked-and-is-not-billable-after-deletesubscriptionaction-on-a-swap-plan-action-request-to-unlock/28009). Importantly, our downgrade code explicitly selects **only the `SWAP_PLAN` action** for deletion. It does not delete all returned actions or any `CHANGE_BILLING_ANCHOR_DATE` action.

We have stopped retrying changes. Could your Subscriptions team please:

- Investigate whether this is a temporary processing lock or requires manual intervention.
- Clear any stuck internal lock or invalid action state.
- Confirm whether the November renewal could be affected.
- Confirm the supported procedure for withdrawing and later restoring a scheduled plan change without causing this issue.

Please do not initiate a charge, cancel the subscription, or create a replacement subscription while investigating.

I can provide the production subscription ID and additional diagnostic details privately to Square staff.

Thank you!

Followup:  
I found related topics #27488 and #28009. Our implementation selects only SWAP\_PLAN actions for removal; it does not delete CHANGE\_BILLING\_ANCHOR\_DATE actions or indiscriminately delete all returned actions.

Could your Subscriptions team inspect subscription `814a2922-00c9-42b5-bf5d-b0e5f9a39ad4`, identify the request that triggered its lock, check for any remaining billing-anchor actions, and repair/unlock it? Please also confirm its next renewal will bill the intended plan correctly.

We have paused further plan-change testing pending your guidance.

---

<div class="post-metadata">

**Author:** ![ashley-square](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@ashley-square](https://developer.squareup.com/forums/u/ashley-square)\
**Post date:** [October 5, 2026, 7:04pm UTC](https://developer.squareup.com/forums/t/production-subscription-locked-after-removing-a-scheduled-plan-change-http-500-on-subsequent-swapplan/28082/3 "2026-10-05T19:04:27Z")

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Thanks for the detailed writeup, and sorry for the trouble here.

This does look related to the recent Subscriptions API cases involving scheduled plan changes, `DeleteSubscriptionAction`, and subscriptions becoming locked after a pending action is removed.

I’m escalating this subscription to the Subscriptions team for review. Specifically, I’ve asked them to check:

- whether the lock is temporary or needs manual repair,
- whether a stale or related billing-anchor action remains internally,
- whether the November renewal is at risk,
- and whether this sequence — deleting a pending `SWAP_PLAN` and later restoring it with another `SwapPlan` — is currently safe.

Please continue to avoid retrying `SwapPlan` or `DeleteSubscriptionAction` on this subscription while the team investigates, since additional mutation attempts can make the state harder to repair.

I also see your note that your code targets only the `SWAP_PLAN` action and does not delete `CHANGE_BILLING_ANCHOR_DATE` actions. That’s helpful and I’ve included it in the escalation.

I’ll update this thread once we hear back from the Subscriptions team.