Sage + ServiceM8 + Make.com: UK Accounting Meets Field Service

Sage Accounting

ServiceM8

Make.com

Why bother with Make.com when ServiceM8 already syncs to Sage?

The moment a job gets marked complete in ServiceM8 is the trigger event the whole pipeline hangs off.

The official answer from ServiceM8 is that they connect to Sage One natively. The real answer, if you actually try it on a UK construction or maintenance business, is that the native connector pushes the approved sales invoice across and not much else. Per the ServiceM8 support docs, once an invoice goes to Sage, any further changes in ServiceM8 stop syncing. Contacts and items move across every 30 minutes, and that is the limit.

For a one-man electrician doing pure private work, that is probably fine. For anyone running CIS subcontract work, purchase invoices from a merchant account, or VAT reverse charge on commercial jobs, the native sync leaves you doing the second half of the work by hand inside Sage every week.

Make.com sits between the two and fills the gap. It catches the ServiceM8 job complete event, pulls the full job sheet, calculates CIS labour deductions, splits materials onto a purchase invoice against the right supplier, and writes the finished PDF back to the job in ServiceM8 so the engineer can show it to the customer the next time they visit. The native connector cannot do any of that.

The three tools and what each one actually does

The architecture is intentionally simple. ServiceM8 is the source of truth for the job. Sage Accounting is the source of truth for the money. Make.com is the wiring between them.

ServiceM8 (the field side)

ServiceM8 captures everything that happens on a job: client details, scheduled date, engineer assigned, materials added, time logged, photos, signatures, completion notes. UK pricing in 2026 starts at £8 per month for the Lite plan (15 jobs), £25 for Starter (50 jobs), £59 for Growing (150 jobs), £119 for Premium (500 jobs) and £269 for Premium Plus (1500 jobs). The Premium plan unlocks margin billing and job costing, both of which matter once you start sending CIS work through.

Sage Accounting (the books side)

Sage Accounting on the UK plans runs from £18 plus VAT per month for Start, £30 for Standard, and £59 plus VAT for Plus. Standard is the one most trades end up on. It includes CIS support, MTD for VAT submission, three users, and payroll for up to five employees. Sage holds a 30 percent plus share of the UK small business accounting market and is the default choice for accountants who came up through the Sage 50 desktop world.

Make.com (the wiring)

Make sits in the middle as the automation engine. The free tier gives you 1,000 operations a month, which is enough for a sole trader with a handful of jobs a week. The Core plan at $10.59 per month gives you 10,000 operations. That is the realistic minimum for a multi-engineer business. Sage Business Cloud Accounting is a first-class app inside Make, with triggers for new sales invoices, purchase invoices, payments and customers, and actions to create or update any of them.

The numbers that matter

Three figures shape whether this integration is worth setting up.

First, the volume. If you run fewer than about 30 jobs a month, the native ServiceM8 to Sage One sync probably does enough and you do not need Make.com in the mix. Past 30 jobs a month, the manual handling of CIS, purchase invoices and adjustments in Sage eats a working day a week. That is the threshold where the maths flip.

Second, the CIS deduction. If you take subcontract work from a main contractor, every labour invoice has 20 percent of the labour value (30 percent if you are not CIS registered) deducted at source and paid to HMRC by the main contractor. Sage Accounting handles CIS natively if you switch it on in Settings, Business Settings, Financial Settings, Construction Industry Scheme. The ServiceM8 native sync does not pass the right flags across, so you end up correcting the deduction by hand on every CIS invoice.

Sage Accounting has CIS baked in but the trigger has to come from somewhere upstream. ServiceM8 does not supply that trigger natively.

Third, the VAT reverse charge. Since March 2021, most building and construction services between VAT-registered businesses go on reverse charge: the customer accounts for the VAT, not the supplier. Sage handles reverse charge correctly when you select the right tax code on the invoice line, but again, the line has to be flagged. Make.com puts the conditional logic into the scenario so the right tax code goes onto the right line every time.

The fourth number worth quoting: from 6 April 2026, every CIS contractor has to file a return every month even when they have paid no subcontractors. So-called nil returns become mandatory. If your books are not in order, that is twelve more chances a year to be late and pick up a £100 penalty.

Prerequisites and credentials checklist

Before you start, line up the following.

1. Sage Accounting account on Standard or Plus (Start does not include CIS). Admin user.
2. ServiceM8 account on Starter or above. Owner-level access so you can install add-ons.
3. Make.com account on the free tier to start with, or Core if you are processing more than 30 jobs a month.
4. Sage Developer app registration for the OAuth client ID and secret (free, at developer.sage.com).
5. ServiceM8 API key from Settings, Add-ons, Developer.
6. Tax codes set up correctly in Sage: Standard 20%, Zero 0%, Reverse Charge CIS 20%, Reverse Charge CIS 5%.
7. CIS turned on in Sage Accounting Settings if you take subcontract work.
8. Test customer in both Sage and ServiceM8 with matching name spelling. Make matches on contact name by default.

Step-by-step setup (90 minutes)

The flow has six setup steps. None of them require code. Block out an hour and a half, get a cup of tea, and work through in order.

Step 1: Register a Sage developer app (15 minutes)

Go to developer.sage.com, sign in with your Sage credentials, and create a new app. Pick Sage Business Cloud Accounting as the API. Set the redirect URL to https://www.integromat.com/oauth/cb/sage-accounting (Make still uses the old Integromat callback). Copy the client ID and client secret somewhere safe. You will paste them into Make in step 4.

Step 2: Generate a ServiceM8 API key (5 minutes)

In ServiceM8, go to Settings, Add-ons, and search for Developer. Install it. Open it, click Generate API Key, and copy the key. ServiceM8 also publishes a webhooks API: this is what we will use to trigger the scenario, rather than polling.

Step 3: Build the webhook trigger in Make (10 minutes)

In Make, create a new scenario. The first module is Webhooks, then Custom Webhook. Add a webhook, name it ServiceM8 Job Completed. Make gives you a URL ending in hook.integromat.com. Copy that URL.

Back in ServiceM8, you cannot add the webhook through the UI on most plans. Use the API directly with curl or Postman. POST to https://api.servicem8.com/api_1.0/event_webhook_subscription.json with your API key in the auth header and a body like this:

{
  "object": "job",
  "event": "completed",
  "callback_url": "https://hook.integromat.com/your-hook-id-here"
}

ServiceM8 confirms the subscription. Mark a test job complete in ServiceM8 and Make will receive the payload. Click Determine Data Structure in Make so it knows what fields to expect.

Make.com's visual canvas is what makes this approachable for trades owners who are not engineers.

Step 4: Connect Sage Accounting (10 minutes)

Add a Sage Business Cloud Accounting module. Make will ask for a connection. Click Create, paste in the client ID and client secret from step 1, give the connection a name, and authorise. Sage opens its OAuth dialogue, you confirm, you land back in Make. The connection token is good for 12 months.

Step 5: Build the job-to-invoice flow (40 minutes)

This is the bulk of the work. The full sequence is described in the next section with the scenario diagram. At a high level: get the job, pull materials, pull activities (time entries), aggregate, route to sales invoice or purchase invoice depending on whether the contact is a customer or supplier, push back to ServiceM8.

Step 6: Test, schedule, and turn it on (10 minutes)

Run the scenario manually first with a test job. Check the invoice appears in Sage with the correct values. Check the PDF gets attached to the ServiceM8 job. Once you are happy, switch the scenario to On. Make checks for new triggers in real time on the Core plan and above (15-minute minimum on free).

The complete Make.com scenario

The scenario runs in sequence. Each module passes data to the next. If any module fails, for example a bad API response or a missing field, Make logs the error and stops the scenario for that run. It does not silently skip or corrupt your data.

How CIS and VAT get handled correctly

This is the part where most off-the-shelf integrations fall over. UK construction VAT and CIS rules are specific, and you cannot fudge them by stripping the deduction out by hand at month end.

CIS deduction has to be calculated and recorded on each invoice line at the point of issue. Retrofitting at month-end is a recipe for mistakes.

CIS labour deductions

The Sage Create Sales Invoice module accepts a CIS deduction value. In the scenario, this is calculated inside the module mapper using a conditional expression: if the client record in ServiceM8 has a custom field client_is_contractor set to true, Make multiplies the labour value by 20 percent (or 30 percent if you swap the constant). If false, the deduction is zero. Sage applies this to the labour line at posting time and the resulting invoice nets the CIS off correctly. The deducted amount lands in Sage's CIS suspense account ready for the contractor to remit to HMRC.

Reverse charge VAT

For commercial CIS work between VAT-registered businesses, the reverse charge applies. The scenario picks the tax code based on the client flag: STANDARD-20 for standard rate domestic, REVERSE-CIS-20 for the reverse charge variant. You set these codes up once in Sage under Settings, Tax Rates. Make picks the right one per line based on the same contractor flag used for the CIS calculation.

The April 2026 CIS changes

From 6 April 2026, three things change. First, mandatory monthly nil returns: if you are a CIS contractor and have paid no subcontractors in the month, you still file a return saying so. Second, public sector payments (local authorities and public bodies) come out of scope. Third, HMRC gets immediate-action powers where a payment is connected to fraud, including stripping Gross Payment Status with no notice.

None of these change how the integration works, but they raise the cost of getting the books wrong. If you are currently scrambling to file CIS returns by hand, the case for automating the pipeline before April 2026 gets stronger by the month. We covered the full picture in our 2026 CIS guide.

Native ServiceM8 to Sage sync vs Make.com routed

Worth being honest about when you need the bigger setup and when you do not. Here is a side-by-side of what each path actually delivers.

The native sync wins for the simple case: a domestic-only trade not doing CIS, fewer than 30 jobs a month, no purchase invoice complexity. Anyone past that point is better off routing through Make.com.

Testing and troubleshooting

Before you turn the scenario on, run three test jobs through it in this order: a domestic non-CIS job, a CIS subcontract job, and a commercial reverse-charge job. Each one stresses a different branch of the logic.

Make's execution log shows every module run. If anything fails, you can replay the bundle after fixing the underlying data.

Common issues and the fix

Cost analysis and ROI

For a four-engineer maintenance business doing 120 jobs a month with about 30 of those being CIS subcontract work, this is the rough maths.

Before automation: roughly 6 hours a week of bookkeeper time at £25 per hour reconciling CIS deductions, raising purchase invoices for materials, and chasing missing job sheets. That is £150 a week, £7,800 a year. Plus the inevitable two or three deduction errors a quarter that cost an extra hour each to fix.

After automation: the bookkeeper spends an hour a week checking Make's execution log and handling exceptions. £25 a week, £1,300 a year. Make.com Core at $10.59 per month converts to roughly £127 a year. Sage and ServiceM8 are already paid for.

Annual saving: £6,373 of bookkeeping time. Payback on the 90-minute setup is roughly two days.

If you also want a dashboard view across the books, the same Make foundation extends nicely. See Commusoft + Sage + n8n: automated P&L by job category for the dashboard layer, and job profitability analysis for the metrics that matter.

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