Payment Terms for Gas Engineering Businesses

Why Payment Terms Matter

Payment terms are more than an admin formality — they directly determine your cash flow. A gas engineering business doing £30,000/month in work on 30-day payment terms has £30,000 tied up in outstanding invoices at any given time. Move to 14-day terms and that drops to £15,000 in working capital released from the cycle.

Clear payment terms also prevent disputes. When a customer knows exactly when payment is due, how to pay, and what happens if they don't, there's no ambiguity to exploit. The most common late payment excuse — "I didn't know when it was due" — doesn't work when your terms are written on every quote and invoice.

Domestic Customers: Best Practice Terms

For domestic homeowners, the clearest and most cash-flow-positive terms:

Small jobs (under £300): Payment on completion, ideally by card on site. No credit extension needed for routine call-outs, services, or minor repairs
Larger jobs (£300–£1,000): Payment on completion or within 7 days by bank transfer. Consider requiring a deposit (20–30%) on booking for jobs in this range
Installations (£1,000+): 20–30% deposit on acceptance of quote; balance on completion. For jobs over £3,000, consider a 3-stage payment: deposit, progress payment, and balance on completion

For domestic customers, the best payment method is card on site (no waiting for bank transfers) or an online payment link in the invoice email. The faster and easier you make it to pay, the faster they will.

Landlord and Letting Agent Terms

Landlords and letting agents are commercial relationships — they understand payment terms and have their own processes. Key considerations:

Small landlords (1–5 properties): Treat similarly to domestic. 14-day terms on invoices, card or bank transfer
Portfolio landlords and letting agents: Many operate 30-day payment cycles aligned to their monthly statements. If you can align your invoicing to their cycle, you'll be included in the monthly run rather than waiting for an ad hoc payment
HMO landlords: Often more business-sophisticated; 14–30 day terms are appropriate. For ongoing service contracts, consider monthly direct debit billing (e.g. £130/month for annual service contract covering all appliances)

For any landlord account you rely on for significant recurring income, get payment terms agreed in writing before starting. A verbal understanding of payment timelines is the most common source of letting agent payment disputes.

Commercial Customers: Navigating Long Terms

Commercial customers — offices, restaurants, schools, care homes — often operate on 30, 45, or 60-day payment terms as standard. This can create serious cash flow pressure for gas engineering businesses where material costs and wages are paid immediately but payment arrives months later.

Strategies for managing commercial payment terms:

Negotiate shorter terms on smaller jobs: Routine maintenance visits (under £500) should be paid within 14–30 days; long payment terms are appropriate for large project work but not routine servicing
Stage payments on large contracts: For PPM contracts billed monthly, set up invoicing at the start of each month for that month's service. This aligns billing with cash needs
Early payment discounts: Offering 2% discount for payment within 10 days (instead of 30) can significantly improve cash flow — you sacrifice a small margin in exchange for predictable early payment
Credit check before extending terms: For first-time commercial customers requesting 30+ day terms, run a credit check (CreditSafe, Experian) to verify their payment history. A company with a poor payment record is not one to extend generous credit to

Including Terms in Quotes and Invoices

Payment terms must be visible and agreed before work starts — not buried in small print no one reads. Include them prominently:

In your quote: "Payment terms: 20% deposit on acceptance; balance due within 14 days of completion"
In your invoice header: "Payment due by [specific date]" — not "14 days" but the actual date calculated from the invoice date
In your terms of business (a separate one-page document given to new customers): all payment terms, deposit policy, late payment policy, and dispute resolution process

When a customer accepts your quote (even verbally), your payment terms apply. If they later dispute the terms, your written quote evidence protects you. This is why quote acceptance should always be in writing — a reply email saying "please proceed" is sufficient.

Frequently Asked Questions

We’re happy to answer all your questions.

What payment terms should a gas engineer use for domestic work?

Payment on completion for small jobs (under £300); within 7–14 days for medium jobs; deposit plus balance on completion for installations over £1,000. Card payment on site or online payment links in the invoice email speeds up payment compared to waiting for bank transfers.

Can I set my own payment terms or must I accept what the customer wants?

You can set your own payment terms. They must be clearly communicated and agreed before work starts. For domestic customers, your quote and invoice terms govern the relationship. For commercial customers, there may be negotiation — but your terms have legal force once accepted in writing.

What are standard commercial payment terms?

30 days is the standard default under the Late Payment of Commercial Debts Act if no terms are agreed. Many large organisations operate 45 or 60-day cycles. You can negotiate shorter terms — 14 days for routine work is reasonable to request, even from commercial customers.

How do I change existing customers to new payment terms?

Notify customers in advance — 30 days' notice is courteous and professional. Frame it as an update to your standard terms, not a punitive change. In practice, few existing customers object to moving from 30 to 14 days if the relationship is good.

What if a letting agent insists on 30-day terms?

Accept 30-day terms for larger accounts but ensure your invoicing is clean, prompt, and aligned with their payment cycle. If you invoice at the start of a month for work done in that month, you'll be in their next payment run — effectively 0–30 days rather than 30–60. The total wait depends on when in their cycle you invoice.