Best Invoicing Software for Gas Engineers UK (2026)

Tradify is the best invoicing software for most UK gas engineers because invoicing is built directly into the job management workflow — raise an invoice from the completed job card in two taps, with VAT, parts, and labour pulled through automatically. Deposit invoicing for boiler installations is included from day one, and automated payment reminders handle chasing without any awkward calls. For engineers who want card payment links on every callout invoice, Jobber is the strongest alternative.

Yes — Tradify and Jobber are both designed to be used from a phone on site. You can create and send a professional VAT-compliant invoice in under two minutes before leaving the customer’s property. For emergency heating callouts where the customer is relieved the boiler is working, invoicing immediately while goodwill is high is the single most effective way to get paid on the day rather than chasing weeks later.

Yes — a deposit of 30–50% before ordering parts for a boiler replacement is strongly recommended. The boiler and installation materials alone can run to £1,200 or more on a mid-range install. If a customer changes their mind or disputes the job after parts are ordered, you’re exposed. A deposit invoice sent before any parts are purchased commits the customer and covers your material outlay. Tradify and Jobber both handle deposit invoicing as standard, making it easy to build this into your standard workflow.

VAT-registered gas engineers must include their VAT number, the VAT rate applied, and the VAT amount on every invoice. Tradify and Jobber both generate VAT-compliant invoices automatically — you set your VAT status once and every invoice is formatted correctly. For quarterly VAT returns, QuickBooks (integrated with Tradify or Jobber) submits directly to HMRC in a fully MTD-compliant format, removing the manual VAT return process entirely.

Gas engineers working as subcontractors under the Construction Industry Scheme must deduct CIS tax (20% for registered subcontractors, 30% for unregistered) from their invoices to contractors. Engineers who use their own subbies must deduct and report CIS correctly on subcontractor payments. Tradify has CIS handling built in, and QuickBooks integrates directly with Tradify to ensure CIS deductions are tracked correctly for year-end returns. Getting CIS wrong is a common and costly mistake — invoicing software that handles it automatically removes the risk.

FreeAgent is completely free for gas engineers who bank with NatWest, RBS, Ulster Bank, or Mettle — covering invoicing, expense tracking, Self Assessment, and MTD compliance. Wave is another free option for basic invoicing, though it lacks VAT return filing and UK-specific features. Tradify and Jobber both offer 14-day free trials with no card required, which is enough time to test the full platform on real callouts and installations before committing.