How does “Reconcile and pay” work on the HMRC Dues page?

Reconcile puts Xero, Saral and HMRC side by side for every company and tax as at a day, with the reason for each difference written on the grid itself — a payment on account, interest, a timing difference — and the journal that would clear it. Post for the whole group sends every reconciling journal across every company in one batch. Payments takes filed liabilities only: a line on a time-to-pay plan or in an open run never appears twice, a pick spanning two taxes makes one run per tax because HMRC's accounts differ by tax, and a bank with no file format yet still joins a run and is paid by hand rather than written into a wrong file. A run reads Downloading until the file is in the browser, and Paid only when the server has seen the bank payment. Where: HMRC Dues (/accounts/hmrc-dues).