Write-back and its guardrails

Write-back pushes a correction back into your PSA. It sits behind four layered limits you control, and every change is reversible.

Write-back carries a fix from your reconciliation list straight into your PSA: it raises or lowers a billed quantity to match what's deployed, or removes a line that has no vendor record behind it. Every change is reversible, and it sits behind four layered limits so a correction only ever happens where you intend.

The four limits

Each limit has to be open for an automatic correction to go through. They stack, narrowest last.

Off until you enable it. Write-back is off for your whole workspace until you turn it on. While it's off, the list is export-only: there's no push button anywhere.
On per connection. Write-back has to be enabled on the specific connection that would do the writing.
Limited to the clients you choose. Only clients you've added to the allow-list can be corrected automatically.
Capped by dollars. A maximum size for any single correction, and a ceiling for a whole run.

Doing it yourself vs letting it run

A manual push shows you exactly what will change (the invoice, the line, the old and new quantity), you confirm, and you can undo it afterward.

An automatic correction runs as part of a reconciliation: only quantity fixes, only on allow-listed clients, only within your dollar cap and run ceiling. Brand-new lines never apply on their own. Anything applied automatically is clearly marked and stays reversible.

The allow-list and caps fence the automatic path

A manual push goes through on any client whose connection has write-back enabled; the allow-list and the dollar caps are there to fence the unattended, automatic path. So turning write-back on also makes automatic corrections possible on every reconciliation, which is why you set the per-connection and per-client limits at the same time.

Built-in safety

It won't overwrite a teammate's edit. If the line changed in your PSA since the last run, the push is refused and tells you the new and expected numbers. Re-run reconciliation first.
It respects term locks. A subscription that can't be reduced right now is never given a reduction it couldn't make.
New lines are export-only on HaloPSA for now. An unbilled item routes to a spreadsheet export rather than creating the invoice line automatically.

For which fix each kind of gap carries, see the five drift types.