Built for small UK businesses on Xero and the practices that serve them. Here's what it actually looks like - pull, prove, lock, and catch anything that moves.
Lock a period and Postlock snapshots every balance and a manifest of the documents behind it - then re-checks on a schedule and flags anything that moves, so you never have to remember to look. It names the invoice, journal, bank transaction or payment, who touched it and when. Because of the manifest, a re-dated document shows the date it held when you signed ("was dated 30 Jun, now 1 Jul"), and one that's voided or deleted after sign-off is a named finding, not a silent hole. Accept a change and you must give a reason: that becomes an audit trail in the pack, not a deletion.
| Account | Was | Now | Movement |
|---|---|---|---|
| Retained Earnings | 1,284,500.00 | 1,282,500.00 | −2,000.00 |
| Type | Ref | Posted | By | Amount |
|---|---|---|---|---|
| Payment | BACS-4471 Pennine Supplies Ltd | 04 Oct 16:22 | T. Okafor | 2,000.00 |
Post-lock detection - the change, the document, the person.
Postlock pulls your balance sheet from Xero and walks you line by line. Each line carries its status, a progress bar, the carried-forward note of what the balance is, and a chip showing whether its supporting schedule ties to the GL.
| Account · what it is | Balance | Status |
|---|---|---|
| Prepayments Insurance + SaaS, straight-lined schedule ties | 9,340.00 | Reconciled |
| Funeral plan cost accrual Monthly accrual vs supplier list △ variance −800.00 | 42,100.00 | In progress |
| Dibble deposit One-off rent deposit, 2024 schedule ties | 10,000.00 | Reconciled |
The monthly close - memory and schedule chips on every line.
Three shapes cover almost everything: movement (opening + additions − releases = closing), balance proof (a list that ties to the GL), and static (an expected value, flagged if it drifts). They roll forward each month on their own and expired items drop off automatically - and every total ties back to the Xero balance.
| Item | From | Opening | Released | Closing |
|---|---|---|---|---|
| Insurance 25/26 | 2025-11 | 4,900.00 | 700.00 | 4,200.00 |
| Software licences | 2026-01 | 5,782.50 | 642.50 | 5,140.00 |
| Total | 10,682.50 | 1,342.50 | 9,340.00 |
A movement schedule, rolled forward and tying to the GL.
Write “what this balance is” once. It carries forward to every future month automatically and prints in the pack, so no balance is ever a mystery again.
One click produces a formatted, multi-tab workbook: cover, balance sheet, rec index with memos, schedules with live formulas, a roll-forward tab, and the post-lock change log. The deliverable your auditor actually wants - usable forever, subscription or not.
Postlock only ever reads from Xero. It can never post, edit or delete anything in your ledger. That's a deliberate trust decision, not a limitation.
Scan your last 6 closed months for anything posted after its period closed - no lock, no baseline, no setup. It's also free before you sign up.
Do the accounts you filed still agree with Xero? One verdict, line-by-line comparatives, and an audit-bundle Excel - every period as locked, plus the year's adjustment register in one file.
Fix-list for the client, handover export for the next FC, board one-pager for the meeting, journal CSV for Xero. None of them needs a Postlock login to be useful - and the templates are free to everyone.
Behind all of it, one conviction. The textbook schedules aren't the pain. The balances nobody can explain are.
Everyone has a sheet for prepayments and accruals. The real pain is the one-off deposit nobody remembers three months later. Every balance-sheet line in Postlock carries institutional memory: a note written once, carried forward every month, printed in the pack.
Connect Xero read-only and check your last 6 closed months in one pass. Prefer to look around first? The demo company needs no sign-up either.