Does an InstaLink expire, and can I use it again?

InstaLinks do not have an expiry date. A link that has not yet been completed therefore does not need replacing simply because it is old.

That does not make a completed link reusable. Once the client completes payment, the link is marked completed and cannot collect another payment. Create a new link for the next request, even when the client is the same. Before sending an older unpaid link again, check that the client and amount are still the request you intend to collect. If the underlying request has changed, confirm the safe correction process with Support rather than assuming the original link can be edited or that it has automatically expired.