> ## Documentation Index
> Fetch the complete documentation index at: https://www.twicecommerce.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Run both systems until 1.0 is finished
> Fulfil pre-switch orders in 1.0, watch 2.0, and know when 1.0 can be closed.
Step 9 of [migrating from TWICE 1.0](/docs/guides/migration/overview). 1.0 keeps every order made before the switch and runs them to completion. 2.0 holds everything from the switch onward.
This is the longest step and the one most often under-planned. **How long it runs is decided by your longest-dated booking, not by you** — if you take bookings a season ahead, 1.0 stays open a season. If everything you sell is fulfilled at the point of sale, this step is days.
## Working 1.0
Fulfil collections, returns, extensions, cancellations and refunds for pre-switch orders **in 1.0**. Release deposits in 1.0, from the 1.0 order.
Bookings dated after the switch are still 1.0's. A customer who booked in 1.0 for a date next month is fulfilled in 1.0 on that date, even though 2.0 has been live for weeks by then.
Do not re-enter pre-switch orders in 2.0. Stock that is out on a 1.0 order is not available in 2.0 — block it there with an internal reservation if you need accurate availability.
## Watching 2.0
For the agreed period after the switch, check daily:
* Every order received its confirmation email.
* The day's collections and returns match what actually happened at the counter.
* Payouts arrive, and the amounts are correct.
* Whether anyone is working around the system. This is the most useful signal you have — a workaround is a defect report from someone too busy to file one.
Hold the scheduled check-in with TWICE for the agreed period. Bring the workarounds.
## Closing 1.0
Keep 1.0 readable until all of these are true:
* Every pre-switch order is closed.
* Every deposit taken in 1.0 is released or charged.
* Every refund owed on a 1.0 payment is handled.
* Finance exports and retained records are stored outside TWICE.
* Your accountant has confirmed they have what they need.
## Common questions
| Question | Answer |
| ----------------------------------------- | --------------------------------------------------------------------------------------------------------- |
| What happens to orders already in 1.0? | They stay in 1.0 and are fulfilled there. 2.0 holds orders made from the switch date onward. |
| Can I run both systems at once? | For fulfilment, yes — you will have to. For taking new orders, no. |
| What happens to deposits I am holding? | They stay in 1.0 and are released from the 1.0 order. |
| When is 1.0 canceled? | Automatically, when your 2.0 trial starts. You do not need to cancel it yourself. |
| When can I stop using 1.0? | After the last pre-switch order is closed, all deposits are released, and your exports are stored. |
| Why am I billed for both? | That is a mistake and you are eligible for a refund. Raise it with your TWICE contact. |
| Something we relied on in 1.0 is missing. | Tell your TWICE contact rather than working around it. It may already exist, or it may be worth building. |
Your 1.0 and 2.0 admin live at the same address. Switch between them with the two-arrows icon in the top right of the admin.
## Related articles
Blocking stock in 2.0 that is out on a 1.0 order.
Reconciling payments and payouts.
Tracing what changed and who changed it.
The full sequence this step belongs to.