For most recurring fire and security work, yes. Maintenance and monitoring contracts repeat on a known rhythm at known prices, and a direct debit costs at most £4.20 per collection, against the staff time an unpaid invoice soaks up. It suits large facilities management and public sector customers less, because they tend to pay only through their own purchase order runs. Neither BAFE nor NSI has any rule on how you get paid, so the choice is yours.
In this article
The short version
- Maintenance and monitoring repeat at known prices on a known rhythm, and one mandate can also carry variable reactive work with advance notice.
- Neither BAFE nor NSI sets rules on payment method, and NACOSS Gold only requires your terms to state the price and annual charges.
- On Adfin's pricing, a £1,440 annual contract costs £4.20 a year to collect upfront or £16.80 a year collected monthly.
- Businesses affected by late payment spend an average of 86 hours a year chasing it, which at £20 an hour is £1,720 of office time.
- Facilities management firms and public bodies usually pay through purchase orders, so offer direct debit to smaller customers, ideally at the annual contract review.
Where direct debit fits a compliance contract book
Most of what a fire and security contractor bills is predictable. Fire alarm servicing under BS 5839-1:2025 happens roughly every six months, so most maintenance contracts carry two visits a year. Emergency lighting, extinguisher and intruder alarm maintenance follow a similar pattern, and monitoring is a flat monthly or annual fee that only changes at a price review.
Predictable amounts on predictable dates are exactly what direct debit handles well. The awkward part of the book is the reactive work on top: call-outs, false alarm visits, replacement detectors and batteries. That can go through the same mandate, since one mandate can collect different amounts on different dates, provided you give the customer notice of each new amount before you collect it.
The certification schemes don't get in the way. BAFE and NSI govern competence and system quality, and NACOSS Gold requires your terms to state the initial price and annual maintenance and monitoring charges. How and when those charges are paid is left to you.
What it costs compared with chasing invoices
Take a monitoring and maintenance contract worth £1,440 a year including VAT. On Adfin's published pricing of 1% + 20p per successful payment, with the percentage capped at £4 for direct debit:
| Billing pattern | Collections a year | Fee per collection | Fee a year |
|---|---|---|---|
| Annually upfront, £1,440 | 1 | £4.20 | £4.20 |
| Quarterly, £360 | 4 | £3.80 | £15.20 |
| Monthly, £120 | 12 | £1.40 | £16.80 |
Set that against chasing. Research for the Department for Business and Trade found that businesses affected by late payment spend an average of 86 hours a year chasing it. At £20 an hour, that's £1,720 of office time before counting the cash you're waiting for. If even a handful of maintenance invoices a year need two or three reminders each, the chasing is likely to cost more than the fees on your whole contract book.
Objections you'll hear and how to answer them
"Our customers won't sign a mandate." Some won't. Facilities management companies, housing providers, public bodies and large corporates usually pay through purchase orders and their own payment runs. Landlords, schools, care homes, shops and offices tend to be far more open to it, especially when the mandate arrives with the contract and not months later.
"Our amounts change every month." Only the reactive work changes, and one mandate can carry variable amounts. Put the collection amount and date on each invoice and it doubles as the advance notice. Many firms collect the fixed charge by direct debit and invoice larger remedial jobs separately.
"The customer can cancel whenever they like." They can, through their bank, at any time. Cancelling the mandate doesn't cancel the contract, though. The charges are still owed and you can collect them another way.
"Customers can claim refunds." The Direct Debit Guarantee gives the customer an immediate refund if a collection is made in error, meaning a wrong amount or a collection they weren't told about. Accurate invoices that carry the collection date keep that risk low.
"We already have mandates with another provider." You don't have to start again. With 10 or more mandates, Adfin moves them across through the Bacs bulk change process and customers don't sign anything. With fewer, customers sign a new mandate.
"It's a lot of set-up." Mostly it's a one-off change to your payment clause and invoice template, then a round of emails to existing customers.
How to move existing customers across
The annual contract review is the easiest moment. The customer is already reading the terms and the price, and adding a mandate to that paperwork is a small extra step. New customers can sign the mandate alongside the contract, so the first service visit is collected automatically.
For customers mid-term, send a short email saying what's changing, the date and amount of the first collection, and a link to sign online. Give them a reason that helps them, such as no more remittance advices or reminders for routine charges. Change the payment clause in your terms before the first collection, and line the first collection up with the next invoice so nobody pays twice in a month.
Some customers sign straight away, some need a nudge and a few will prefer to keep paying by transfer, which is fine. Adfin chases unsigned mandates for you and offers those customers another way to pay in the meantime, so nobody on your team has to keep a list of who's still outstanding. For the invoices that stay off direct debit, and any collection that fails, its AI agents can chase over email, SMS or WhatsApp on the schedule you set, retry failed payments and send a statement when a customer goes quiet, with you approving what goes out.
Common questions
Does BAFE or NSI require fire and security firms to take payment in a particular way? No. Neither scheme sets payment terms or methods. NACOSS Gold requires your terms to state the initial price and annual maintenance and monitoring charges.
Can one direct debit mandate cover both monitoring fees and call-outs? Yes. One mandate can collect different amounts on different dates, with advance notice whenever the amount or date changes.
What does a direct debit collection cost? On Adfin's published pricing, 1% + 20p with the percentage capped at £4, so no single collection costs more than £4.20.
What if a customer cancels their direct debit partway through a maintenance contract? The contract still stands. Invoice the remaining charges and collect them by card or bank transfer until a new mandate is in place.
Is direct debit a good idea for facilities management customers? Often not. Large facilities management companies and public bodies usually pay only through purchase orders, so direct debit fits small and mid-sized end customers much better.
Can I move mandates from my current provider without customers re-signing? Yes, if you have 10 or more; they move through the Bacs bulk change process. With fewer than 10, customers sign a new Adfin mandate.
Sources
- National Security Inspectorate - NACOSS Gold approval criteria SF 002 Issue 9 (accurate as of September 2026) https://nsi.org.uk/wp-content/uploads/2012/06/SF-002.9-NACOSS-Gold-approval-criteria-Oct-2024.pdf
- Fire Industry Association - Guide to the changes in BS 5839-1:2025 (accurate as of September 2026) https://www.fia.uk.com/static/77c28e9f-486e-4b96-a82e4bb37f4f3882/Guide-to-the-changes-in-BS-5839-1-2025.pdf
- Bacs - Direct Debit: an introduction to the service (accurate as of September 2026) https://www.bacs.co.uk/media/pu4bmlzs/dd_introduction.pdf
- Pay.UK (Direct Debit) - Direct Debit Guarantee (accurate as of September 2026) https://www.directdebit.co.uk/direct-debit-guarantee/
- Department for Business and Trade / London Economics - Late payments research: impact on the UK economy (accurate as of September 2026) https://assets.publishing.service.gov.uk/media/688a089a6478525675738ff9/late_payments_research_impact_on_uk_economy.pdf
- Adfin - Pricing (accurate as of September 2026) https://www.adfin.com/pricing
