How to Keep Your Trade Invoices and Payments in Sync with Xero Without Double Entry (2026)

If you are raising a job in one system and the invoice in another, month end is a spreadsheet exercise: working out which invoices are actually paid, which customer you already have on file under a slightly different name, and which VAT code someone typed by hand instead of picking from a list. The fix is a genuine two-way sync, where invoices, payments, customers and VAT codes move automatically in both directions between your job management software and Xero, not a one-way push that only sends data out. Checker syncs both ways with Xero: every invoice you raise and every payment you take flows automatically between Checker and Xero, so the job and the money you were paid for it stay the same record in both places.

If you are still weighing up which job management software to pair with Xero in the first place, our guide to the best job management software that integrates with Xero for UK trades covers that decision. This guide picks up from there: what to expect once the sync is switched on, and how to run reconciliation without creating extra work for yourself.

What actually happens when the job and the invoice live in two systems?

Picture the ordinary version of this. An engineer finishes a boiler service, raises the invoice on their phone before leaving the driveway, and takes a card payment there and then. Back at the office, whoever handles the books either re-keys that invoice into Xero from scratch, or waits until month end to do a batch of them together. Somewhere in that gap, a payment gets missed, a VAT rate gets typed wrong, or the customer gets created twice because the office did not know the engineer had already added them on site.

None of this is because anyone is careless. It is what happens by default when the job system and the accounting system are two separate places that only meet when a person manually carries information between them. The invoice total might match, mostly, but proving it took someone sitting down with two screens open, and any job that got missed does not surface until a customer chases a receipt or an accountant asks why a job shows as unbilled three months after it was done.

A two-way sync removes the manual carrying. It does not remove the need to check your figures at month end, but it changes what that check involves: confirming the sync worked, not re-entering the sync’s job by hand.

What is the real difference between a two-way sync and a one-way push?

“Syncs with Xero” gets used loosely, so it is worth being specific about what the two versions actually do.

A one-way push sends data outward only, usually invoices and customer records moving from the job app into Xero. That is genuinely useful, it means invoices do not need re-typing, but it stops there. If a payment gets reconciled in Xero, the job app does not know. If an invoice gets edited in Xero, the job app is now out of date. Xero’s own bank reconciliation screen matches imported bank lines to existing invoices using suggested matches based on amount, date and contact, and that reconciliation state, paid or not, lives inside Xero. A one-way push has no route back out of Xero to tell the job app that state changed, so the job still shows as unpaid or open somewhere else, and someone has to notice and fix it.

A genuine two-way sync closes that gap. Every invoice you raise and every payment you take flows automatically both ways between Checker and Xero, QuickBooks or Sage, so reconciling a payment in Xero is the same action as marking it paid in the job app, because they are the same record.

It is worth checking this distinction for whichever accounting package you actually use: do not assume it behaves identically across all of them. Checker connects to Xero, QuickBooks and Sage, but documents the depth of that connection separately for each: Xero’s sync is described as full two-way, where QuickBooks and Sage have their own documented behaviour for what flows back. The lesson generalises beyond Checker: confirm what comes back out of the accounting package as well as what goes into it, before you rely on either direction at month end.

What exactly moves between Checker and Xero?

Per Checker’s own accountancy integrations page, this is what the sync covers:

• Invoices. Line items, quantities, prices and notes, beyond a single total figure, so the detail behind the number is visible on both sides.



• Payments. Log a payment on either side and it reconciles on the other. A card payment taken on site in Checker shows as paid in Xero without a separate entry, and a payment reconciled against a bank line in Xero shows as paid back in Checker.
• Edits. Changes made to an invoice in Xero update Checker, so the two records stay level whether the accountant made the correction or the person who raised the job did.
• Customers. New customers are created and matched on both sides automatically, with no separate contact to build manually in Xero for every job.
• VAT codes. 20%, 5%, 0% and exempt are all supported. Xero’s own default tax rate settings apply in a set order when a transaction is created, the contact’s default first, then the item’s default, then the account’s default, so it is worth knowing that order exists if a code ever looks different from what you expected.
• CIS deductions. Xero calculates and records CIS deductions on a bill and posts the corresponding entry to the CIS liability account, with the subcontractor deduction rate set at 20% for a registered subcontractor or 30% for one who is not registered or cannot be verified. Checker’s sync carries CIS deductions through to Xero automatically, so they do not need to be applied separately.
• Credit notes and part-payments. Both sync, and in Xero a credit note is allocated against an existing invoice to reduce the amount owed; the original invoice line is not altered after the fact.

What is the lock date, and why does it protect your reconciliation?

The lock date is the cutoff you set when you connect Checker to Xero, QuickBooks or Sage. Every invoice and payment dated on or after that date flows both ways in the background: raise it in Checker and it appears in your accounts, reconcile it in Xero and Checker knows.

This is a different control from Xero’s own lock dates, and it is worth understanding both. Xero has a Reporting Period lock date and an End of Year lock date, set separately inside Xero’s financial settings under the Advisor role, and they restrict who can edit a transaction dated on or before the lock date, no matter where that transaction came from. Checker’s lock date decides what is eligible to sync at all; Xero’s lock dates decide who, if anyone, can still change a transaction once it exists. Used together, they mean a job invoiced and reconciled last quarter is not quietly disturbed by a sync running this quarter, and it is not accidentally editable by someone in Xero either.

What does a practical month-end routine look like?

A two-way sync does not remove reconciliation as a task, it removes the re-keying that used to sit underneath it. A short routine covers what is left:

1. Confirm the lock date. Before you close a period, check that Checker’s lock date matches the period you are about to reconcile in Xero, so nothing from an earlier, already-closed period is still expected to sync.
2. Reconcile in Xero as normal. Run the bank reconciliation screen, matching imported bank lines to invoices using Xero’s suggested matches. Because payments logged in Checker already flow through, most lines should already have an obvious match, with nothing needing to be created from scratch.
3. Check for duplicate contacts. Scan for any customer that appears twice before merging anything. If a duplicate exists, use Xero’s own merge process, which archives the record you are removing and combines its transaction history onto the one you keep, and can be reversed if you merge the wrong pair.
4. Spot-check VAT codes. Pick a handful of invoices raised that period and confirm the VAT code that landed in Xero matches what was actually charged in Checker, particularly if you have recently changed a default tax rate on a contact or account in Xero.
5. Reconcile CIS deductions. If you deal with CIS, check the deductions recorded against the payment and deduction statements you issued that month.
6. Move the lock date forward. Once the period is closed and both systems agree, move Checker’s lock date forward to the start of the next period, ready to go again.

What are the common failure modes, and how do you avoid each?

Duplicate customer records. This usually happens when a customer is created manually in Xero even though a matching record already exists from the Checker sync, or the other way round, most often when someone is working quickly on site and someone else is working quickly in the office at the same time. Letting Checker create and match customers automatically, instead of adding them separately in Xero, avoids most of this. Where a duplicate does appear, use Xero’s merge feature to fix it: deleting one manually loses the transaction history that merging keeps.

Mismatched VAT codes. A code that looks wrong is often not a sync fault but Xero’s own default tax rate order asserting itself, the contact’s default, then the item’s default, then the account’s default, overriding what was expected. Checking those defaults on the Xero side, alongside the VAT code chosen in Checker, closes this gap faster than assuming the sync itself is broken.

Payments logged twice. This happens when a payment that already came through Checker, a card payment taken on site for example, is also entered as a new receive-money transaction directly in Xero’s bank reconciliation screen, instead of matching it against the invoice that already exists. The habit that prevents it: use the suggested-match option in Xero and skip creating a fresh transaction.

Editing a synced invoice. Edits made in Xero do update Checker, so the two stay level either way. Even so, the steadier habit is to make changes in Checker, where the job record started, so the job history and the invoice keep telling the same story later. Once an invoice has been reconciled, use a credit note allocated against it and leave the original line unchanged, which is also how Xero itself expects a reconciled invoice to be adjusted.

Which Checker plan do I need for the Xero sync?

Accounts sync with Xero, QuickBooks or Sage sits on Checker Pro and above, at £19.99 a month. Checker Lite, at £10.99 a month, includes unlimited invoicing, quoting and job sheets, but has no CRM, no reminders and no accounts sync. If double entry between your job app and Xero is the problem you are trying to solve, Lite will not solve it. Pro+, at £25.99 a month, adds unlimited sub users on top of everything Pro includes.

The trial does not need card details, so it is possible to connect a real Xero organisation, set a lock date, and raise a real invoice to see the sync work before choosing a plan. Pro also includes the automations that keep an invoice from stalling before it ever needs reconciling, an invoice chaser once payment terms expire alongside the appointment and quote chasers, so fewer invoices arrive at month end unpaid in the first place.

Frequently asked questions

Authoritative sources

1. Checker: accountancy integrations
2. Xero Central: default tax rates
3. Xero: reconcile bank transactions
4. Xero Central: set up and work with lock dates
5. Xero Central: Construction Industry Scheme (CIS) in Xero
6. Xero: Construction Industry Scheme guide
7. Xero: merge contacts
8. Xero: credit notes explained

This guide describes Checker’s own documented Xero sync behaviour and Xero’s own published features. Confirm current behaviour inside your own Checker and Xero accounts, since account-level settings can change what you see.