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Construction Software That Connects To Xero

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Problem: The same construction numbers get entered twice — once to approve them on the project, once to get them into Xero — and CIS deductions and reverse-charge VAT get patched by hand somewhere in between. Outcome: Connect Xero once over OAuth. Approved bills, CIS subcontractor payments, sales invoices and site timesheets reach Xero with the deduction, the VAT treatment and the source document already correct.

In Short

Site Samurai connects to Xero over the official Xero OAuth API. Approved supplier bills, CIS subcontractor payments and sales invoices raised from your applications for payment post straight into Xero as native records, with the source PDF attached and domestic reverse charge VAT already applied. Draft bills pull back the other way for three-way matching against your POs and GRNs, and paid status flows back so the project view matches the ledger. Approved site timesheets can also post to Xero Payroll as timesheet lines — a path that exists for Xero and not for Sage. It is included on Professional at £199 per month with unlimited users, and there is no per-seat pricing on any plan.

Official Xero API, both directionsCIS deductions applied before postingDomestic reverse charge handledApproved timesheets to Xero Payroll

See It In Action

Connect your Xero organisation, map your accounts once, and see every push and pull with its outcome.

Xero Connection And Sync Log
Accounting / Xero
Xero Connection And Sync Log

OAuth connection to your Xero organisation

Pick which Xero organisation to post to

Chart of accounts fetched live from Xero

Approved bills and invoices post automatically

Paid status reconciled back from Xero

Status
Connected
Last sync
Just now
Workflow
Connect → Configure → Sync → Monitor
Auto / Manual

Example UI preview. Book a demo to see your exact workflow.

How It Works

The connector talks to the Xero API in both directions. Here is the actual sequence, start to finish:

  1. 1

    Authorise Xero over OAuth

    You sign in at Xero and grant access. Site Samurai never sees or stores your Xero password — only encrypted access and refresh tokens, which you can revoke from Xero at any time.

  2. 2

    Choose which Xero organisation to post to

    If your Xero login covers more than one organisation, you select the one this company posts to, so a group keeps each entity on its own ledger.

  3. 3

    Map your accounts

    Site Samurai reads your chart of accounts live from Xero, so labour, materials, plant and subcontractor costs map onto the account codes you already use.

  4. 4

    Approve once, post automatically

    Approved supplier invoices post as bills, CIS subcontractor payments post with the deduction applied, and sales invoices raised from applications for payment post as invoices — each with the source PDF attached to the Xero record.

  5. 5

    Pull draft bills back for matching

    Bills entered directly in Xero can be pulled into Site Samurai and matched against the purchase order and goods received note, so the three-way match runs against real ledger data.

  6. 6

    Reconcile payments and post timesheets

    Paid status flows back from Xero so outstanding balances stay honest, and approved employee timesheets can post to Xero Payroll against your chosen pay calendar and earnings rate.

Integration Features

Everything you need to connect Xero with your construction workflows.

Official Xero API

A live OAuth connection to Xero. Documents are created as native Xero records — there is no CSV export and no import step on your side.

CIS-correct subcontractor bills

The 0%, 20% or 30% deduction recorded against the subcontractor is applied before the bill reaches Xero, so it posts with the deduction already right.

Domestic reverse charge VAT

Invoices marked domestic reverse charge post against your nominated Xero reverse-charge tax rate, and the invoice PDF carries the customer-accounts-for-VAT wording.

Timesheets to Xero Payroll

Approved employee timesheets post to Xero UK Payroll as timesheet lines against your chosen pay calendar and earnings rate. This path exists for Xero and not for Sage.

Source documents travel with the bill

The supplier invoice PDF is uploaded to the Xero record as an attachment, so the evidence opens from inside Xero.

Draft bill import and three-way matching

Draft bills pull from Xero into Site Samurai and match against the purchase order and GRN, so quantity and price disputes surface before payment.

Contact sync with payment details

Clients, suppliers and subcontractors are created and updated as Xero contacts, carrying bank details, payment terms and tax number so payment runs are not rebuilt by hand.

Credit notes and corrections

Credit notes and voids are pushed against the original document rather than left as a manual correction at month-end.

Paid status reconciliation

Invoices marked paid in Xero are reconciled back, so the project view of what is outstanding matches the ledger.

Use Cases

Accounts teams

Stop rekeying approved construction bills into Xero — they arrive as native records with the PDF attached.

Payroll and CIS teams

Post subcontractor payments with the correct deduction applied, and push approved site timesheets into Xero Payroll instead of retyping hours.

Quantity surveyors

Raise the application for payment once; the resulting sales invoice reaches Xero without a second entry.

Commercial managers

Match supplier bills against the PO and GRN before payment, using bills pulled straight from the ledger.

Finance directors

Close the month against a ledger that already carries project costs and paid status.

Who It's For

  • UK contractors already running Xero
  • Firms paying CIS subcontractors who want the deduction right before it reaches the ledger
  • Accounts teams rekeying approved invoices out of a project system into Xero
  • Businesses applying domestic reverse charge VAT on construction supplies
  • Teams running Xero Payroll who want approved site hours posted rather than retyped

Who It's Not For

  • Anyone expecting Site Samurai to file the CIS300 monthly return. It does not. You still file at HMRC or through your accounting package; we give you clean line-level data to reconcile against it.
  • Anyone expecting a live HMRC lookup at the moment you add a subcontractor. Site Samurai records the verification number and rate HMRC gave you and applies it consistently — it does not call HMRC for you.
  • Teams wanting purchase orders themselves mirrored into Xero. POs drive matching inside Site Samurai and appear as a reference on the bill, but the PO document is not created in Xero.
  • Organisations wanting Xero and Sage connected at the same time. One accounting connection is active per organisation; you choose Xero or Sage.
  • Anyone who needs the accounting connection on the entry plan — it is a Professional feature at £199 per month, not part of Starter.
FAQ

Frequently Asked Questions

Common questions about the Xero integration.

Over the official Xero OAuth 2.0 flow. You authorise the connection at Xero, and Site Samurai stores only encrypted access and refresh tokens — never your Xero password. You can revoke the connection from Xero at any time, and the requested scopes cover accounting transactions, contacts, attachments and payroll timesheets.
No. There is no file anywhere in the flow. Approved documents are created directly in Xero as native records over the Xero API, and draft bills are pulled back the same way. Nobody downloads a file and nobody runs an import in Xero.
Approval is the trigger. Approved supplier invoices post as bills; approved CIS subcontractor payments post as bills with the deduction applied; sales invoices — including those raised from an application for payment — post as invoices. Clients, suppliers and subcontractors are created and updated as Xero contacts, credit notes and voids are pushed against the original document, and approved employee timesheets can post to Xero Payroll.
Each subcontractor carries their HMRC verification number and the resulting deduction rate — 0% for gross payment status, 20% verified, or 30% unmatched — stored against the record with the UTR and NI number encrypted. That rate is applied to every payment, and if a subcontractor is re-verified at a different rate the change cascades forward to entries that have not yet been approved. The bill that reaches Xero already carries the correct deduction.
No, and we will not imply otherwise. Site Samurai records the verification number and the 0%, 20% or 30% rate that HMRC returned to you and then applies it consistently to every payment, with a re-verification cascade when a status changes. The verification itself is still something you do through HMRC. The value is in applying the right rate every time, not in the lookup.
No. You file the CIS300 through HMRC online services or your accounting package. What Site Samurai gives you is clean line-level deduction data — per subcontractor, per payment, per period — so reconciling the return is a check rather than a rebuild.
You nominate the Xero tax rate that represents the CIS domestic reverse charge, and invoices flagged as reverse charge post against it rather than falling through to standard 20% VAT. The invoice PDF states that the customer accounts for VAT and that the amount payable excludes it.
Yes, and this is the one place the Xero integration goes further than the Sage one. Approved employee timesheet entries post to Xero UK Payroll as timesheet lines against the pay calendar and earnings rate you nominate. There is no equivalent payroll path for Sage.
Yes. Draft bills can be imported from Xero into Site Samurai and matched against the purchase order and goods received note for a genuine three-way match. Only draft bills are pulled, and CIS subcontractor bills are filtered out so they are not double-counted against the payments Site Samurai already posted.
No. One accounting connection is active per organisation, so you choose either Xero or Sage. If different companies in a group use different accounting software, each runs as its own organisation in Site Samurai with its own connection.
Professional, at £199 per month, which also covers purchase orders, GRNs, three-way matching, supplier and sales invoices, estimating, RAMS and API access. Starter is £99 per month and Enterprise is £699. Every plan includes unlimited users — there is no per-seat pricing on any plan — and there is a 14-day free trial.
The failure is recorded against the document with the reason from Xero, and every push and pull is written to a sync log. A failed sync stays visible and retryable rather than disappearing, which matters because a bill that silently never reached the ledger is the expensive kind of error.
No. Purchase orders drive approval and three-way matching inside Site Samurai and appear as a reference on the bill that posts to Xero, but the PO document itself is not created in Xero. We would rather say that plainly than let you find out at month-end.

Related Solutions

Applications for Payment

Interim valuations with Construction Act 1996 s.111 pay less notice tracking, and a sales invoice that reaches Xero without a second entry.

Learn more
CIS Management

Verification numbers and 0%, 20% or 30% rates recorded per subcontractor and applied to every payment.

Learn more
Supplier Invoices

Approval workflow with three-way PO, GRN and invoice matching before anything reaches the ledger.

Learn more
Subcontractor Management

Onboarding, insurance monitoring and encrypted document storage for the subcontractors you pay under CIS.

Learn more

Other Integrations

SageView all integrations →

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