Sound familiar?
- Invoices are built in a spreadsheet each month and take days
- Meter readings or usage data arrive as CSVs that someone has to reformat
- Mid-month price changes and pro-rating cause errors and credit notes
- Customers query bills and nobody can quickly show how they were calculated
- Chasing late payments is manual and inconsistent
Key facts
- dijitul first built automated billing software to invoice energy usage: electricity, water and gas
- Handles meter reads, usage tiers, standing charges, pro-rating and VAT
- Recurring contracts with indexation, minimum terms and mid-period changes
- Invoices posted to Xero, QuickBooks Online or Sage through their APIs
- Payment collection by Stripe card payments or GoCardless Direct Debit
- Every invoice line traceable to the reading, rate and rule that produced it
Where this started
Billing software is one of the oldest things dijitul developments builds. Our first automated billing system was written to invoice customers for energy usage: electricity, water and gas. That work forced us to get the hard parts right early: importing readings, handling estimated and actual reads, applying tariffs that change partway through a billing period, pro-rating standing charges, and producing invoices a customer could check line by line.
The same problems turn up in many industries. Anyone who bills on what was used, rather than a fixed monthly fee, needs the same engine underneath.
Who needs automated billing
- Landlords and property managers recharging utilities to tenants from sub-meters, a common need covered on software for property.
- Energy and utility service businesses billing metered supplies, heat networks or EV charging. See software for energy and utilities.
- Managed service providers and telecoms resellers billing per user, per device or per minute from supplier usage files.
- Equipment hire and rental firms billing by day, week or usage hours.
- Subscription and membership businesses with add-ons, credits and contract terms beyond what a simple subscription tool handles.
How the billing engine works
Underneath every system we build is the same pipeline:
- Import usage. Readings or usage records arrive by CSV upload, SFTP drop, a supplier API or a meter data platform. Each import is validated: missing reads, negative consumption, impossible jumps and duplicate files are flagged before billing.
- Rate it. A rating engine applies the right tariff for each customer and date range: unit rates, tiered or banded pricing, day and night rates, standing charges, minimum charges, discounts and the correct VAT rate. When a price changes mid-period, consumption is split and pro-rated.
- Draft the run. A billing run creates draft invoices and a summary of totals, exceptions and changes against last period, so someone can sanity-check before anything is sent.
- Issue and post. Approved invoices are generated as PDFs, emailed, and posted to your accounting package with the right account codes and tax rates.
- Collect. Payment is taken by card or Direct Debit, and reminders go out automatically for anything overdue.
Every invoice line stores which reading, tariff and rule produced it. When a customer queries a bill, you can show the working in seconds.
Accounting and payment collection
We normally keep your accounting package as the ledger and let the billing system feed it. Invoices and credit notes are posted through the Xero API, QuickBooks Online API or Sage, each with an idempotency check so a retried request never creates a duplicate invoice. Payment status flows back so the billing system knows who has paid. Our long history of accounting software integration, going back to KashFlow, shapes how we handle rounding, credit notes and part-payments.
For collection, GoCardless suits variable Direct Debit amounts well, because the mandate covers amounts that change each period with advance notice to the customer. Stripe suits card payments and customers who prefer to pay online. Failed payment webhooks trigger retries and reminder emails rather than silent arrears. See payment gateway integration.
Accuracy, audit and VAT
Billing errors cost twice: once in the credit note and again in customer trust. We write automated tests for every tariff rule with known inputs and expected outputs, including the edge cases: leap years, clock changes, tariff changes on the first and last day of a period, and meter rollovers. Rounding is applied consistently at the line or invoice level to match how your accountant expects VAT to be calculated.
Changes to tariffs and customer contracts are logged with the user and date. If a price was wrong for a period, the system can calculate the correction and raise the credit or extra charge automatically.
Getting started
A billing project starts with a free chat and a look at your current invoices, tariffs and data files. We then scope the rules in writing and give a fixed-price quote. Customers can be given a billing portal to view usage, download invoices and pay. It is part of our wider bespoke software development work. Get in touch to talk it through.
What we deliver
- Customer, site, meter and contract records
- Usage import from CSV, SFTP, API or meter data platforms
- A rating engine for tariffs, tiers, standing charges and discounts
- Draft invoice runs with review, approval and bulk issue
- Accounting sync and payment collection
- Customer statements, reminders and a billing portal
How it works and what it costs
Every project gets a fixed-price quote after a free initial chat and a short scoping stage. You own the code and the data.
Free chat
Tell us the problem in plain English: what you do now, what goes wrong and what "better" looks like. No charge, no obligation.
Scoping
We map the processes, systems and data involved, agree what is in and out, and write it down so there are no surprises.
Fixed-price quote
You get a fixed price for the agreed scope, or a phased plan for bigger builds, so you can start small and prove it works.
Build and test
We build in short stages you can see and try, test against real data, then go live carefully with a rollback plan.
Hand over and look after
You own the code and the data. We can host it, support it and keep improving it, or hand it to your own team.
Frequently asked questions
Can it bill for utilities recharged to tenants?
Yes. dijitul first built automated billing software to invoice customers for electricity, water and gas usage. We import sub-meter readings, apply your tariffs and standing charges, pro-rate changes and issue invoices that show the working on every line.
Will invoices go into Xero automatically?
Yes. Approved invoices and credit notes are posted through the Xero API with the correct account codes and VAT rates. dijitul builds in idempotency checks so a retried request never creates a duplicate, and payment status flows back from Xero.
Can customers pay by Direct Debit?
Yes. dijitul integrates GoCardless for Direct Debit, which suits variable monthly amounts, and Stripe for card payments. Failed payments trigger retries and reminders automatically, so arrears do not build up unnoticed.
What if a tariff changes mid-month?
The rating engine splits consumption at the change date and applies each rate to its own portion, pro-rating standing charges in the same way. Every calculation is stored, so the invoice shows exactly how the total was reached.
How do you make sure bills are right?
Every billing run is created as a draft with totals, exceptions and comparisons against last period for review. dijitul writes automated tests for each tariff rule, including edge cases such as clock changes and meter rollovers.
How much does billing software cost?
dijitul quotes each project after a free chat and a scoping stage, because the number of tariffs, data sources and integrations varies so much. You receive a fixed-price quote for the defined scope before work starts.
Related
Tell us what you need to build
Free chat, clear scope, fixed-price quote. You own everything we build.