Ben SnapeBilling software for architects needs to fit the way a practice charges for work: agreed project stages, recorded time or a combination of both. Compare how each option connects the fee proposal, completed work, invoice and payment record.
A practice billing several projects at different stages needs a clear record of what is ready to invoice and what the client has already paid. This guide compares invoicing options for UK architecture firms and the workflows to check before choosing one.
As we have covered in several posts on this blog (including our guide to fee structures, invoicing mistakes, our project accounting software guide, our time tracking and billing guide, and our cash flow breakdown), the billing layer of a practice’s operations has an outsized effect on cash flow, client relationships, and overall financial health.
The options below cover different combinations of project billing, practice records and accounting. Use your own billing process to assess which features matter.
Why billing and invoicing is a bigger problem than it looks
A practice that cannot invoice promptly and accurately has a cash flow problem, whether or not it feels like one.
Architecture fees are typically paid in stages tied to RIBA Plan of Work milestones: a percentage at Stage 2, a larger tranche at Stage 4, and so on. That makes fees structurally lumpy. But the gap between stages is only as short as the team and the systems make it.
When the invoices are then prepared manually, without reference to the original fee proposal, they can be delayed and inaccurate. When they are inaccurate, clients query them, payment is delayed further, and the principal spends time on disputes that should never have arisen. Our operational bottlenecks post identified late and inaccurate invoicing as one of the single most consistent sources of cash flow pressure in small and mid-sized practices.
The solution is not just better invoicing software in isolation. It is billing software that connects to the rest of how the practice manages its projects, so that the invoice is a natural output of the project workflow.
The best billing and invoicing software for UK architecture firms
1. PlanMan the best all-in-one billing platorm for UK architects
PlanMan.app – from £54/month – 30-day free trial, no card required
PlanMan is the only tool on this list built specifically for UK architects and town planners, and that specificity is most visible in how billing and invoicing work.
Rather than treating invoicing as a standalone module, PlanMan connects it to every other part of the project workflow, which is exactly what an architecture practice needs.
When a project stage is marked complete, an invoice can be generated at the click of a button, pre-populated with the client details, project name, stage description, and fee amount from the original quote.
The quote management module feeds the invoice management module, which feeds payment collection, which feeds the accounting integration. It is a single workflow rather than a sequence of separate tools.
The practice dashboard gives principals an overview of all live projects, including open quotes, forecast fee values, and monthly billing status.
For payment collection, PlanMan integrates with both Stripe (card payments) and GoCardless (direct debit), allowing clients to pay directly from the invoice. For accounting, it syncs with Xero, FreshBooks, and Sage, so all invoice data flows to whichever accounting platform your accountant uses.
The rest of the platform compounds the value: client communication and project-level chat are stored against the same project record as the invoice, so if a client queries a charge, the entire correspondence history is immediately accessible.
Document management means the fee agreement, the original quote, and the stage-completion evidence all sit alongside the invoice, as well as all the major design deliverables. The mobile app makes all of this accessible from site visits or client meetings.
PlanMan is best for: any UK architecture or town planning practice that wants invoicing to be part of the project workflow rather than a separate task. Particularly strong for practices running multiple concurrent projects and those tired of reconciling billing against project progress in separate systems.
2. Xero – best dedicated accounting platform
Xero.com/uk – from £16/month (Ignite) – 30-day free trial
Xero is the UK’s dominant cloud accounting platform and what most UK accountants already know and prefer. Its invoicing is clean, customisable, and reliable.
You can create branded invoices, set up recurring billing, automate payment reminders, and accept online payment directly from the invoice. Bank feeds from all major UK banks update automatically, and VAT submissions to HMRC are MTD-compliant on all plans.
For architects specifically, Xero’s strength is that it is what your accountant already uses, but its weakness is that it knows nothing about your projects.
An invoice in Xero is not connected to a design stage, a fee proposal, or a client communication: it is just a financial document that must be constructed separately from whatever project management system the practice runs.
For practices that want billing to emerge naturally from project progress, Xero alone does not deliver that. The natural pairing is Xero for accounting alongside PlanMan for project management and invoicing, using the PlanMan–Xero integration to sync invoice data automatically.
3. FreshBooks – best for sole traders and freelance architects
Freshbooks.com/en-gb – from £16/month (Lite) – 30-day trial
FreshBooks was built for freelancers and sole traders and remains the most user-friendly invoicing and accounting option at the small end of the market.
Creating and sending an invoice takes minutes, the time-tracking module integrates directly with billing (useful for hourly-rate work), and the mobile app is well-regarded. Automated payment reminders and recurring invoices reduce manual chasing.
FreshBooks is also directly integrated with PlanMan via the PlanMan–FreshBooks sync.
The limitations become clear as the practice grows: most plans cap the number of clients you can invoice (5 on Lite, 50 on Plus) and additional team members cost £8/month each on top of the subscription.
Reporting depth is limited compared to Xero or Sage, and double-entry accounting tools are restricted to higher plans.
4. FreeAgent – best free option for NatWest/RBS account holders
Freeagent.com – free with NatWest/RBS/Ulster Bank/Mettle business account – From ~£19/month otherwise
FreeAgent is UK-built cloud accounting software (launched in Edinburgh in 2007, acquired by NatWest Group in 2018) with a strong reputation for its invoicing, time tracking, and UK tax filing features. It is MTD-compliant for VAT and Self Assessment, handles Corporation Tax calculations, integrates directly with HMRC, and connects to major UK bank feeds including challenger banks such as Starling, Monzo, Tide, and Revolut Business.
What makes FreeAgent particularly relevant for sole practitioners and small practices is cost: if you hold a business current account with NatWest, Royal Bank of Scotland, Ulster Bank, or Mettle (NatWest’s free digital business account), you get the full version of FreeAgent at no extra charge, for as long as you retain the account.
That saves between £50 and £396 per year compared to paying directly. Mettle itself has no monthly fee and no minimum balance, so opening a Mettle account purely to access free FreeAgent is a legitimate strategy for very small practices.
The trade-off is limited complexity handling: no multi-entity support, no multi-currency invoicing in lower tiers, and no CIS contractor reporting (important for practices working with subcontractors).
5. Sage Accounting – best for practices with established accountants
Sage.com/en-gb/sage-business-cloud/sage-accounting – from £15/month (Start) – 30-day trial
Sage is the longest-established name in UK accounting software, with a particular stronghold among practices whose principals have used desktop Sage products, or whose accountants are Sage-certified.
The cloud product Sage Accounting covers invoicing, expense tracking, bank reconciliation, MTD-compliant VAT returns, and payroll on all plans, with payroll included at no extra subscription cost.
UK-based telephone support is another real advantage: when a VAT return goes wrong or a payroll run misfires, being able to call someone and get it resolved quickly is worth paying for (Xero routes most UK support through online channels).
Like all dedicated accounting platforms, Sage has no awareness of RIBA stages, fee proposals, or project-specific milestones, so invoicing is entirely separate from the project workflow.
The PlanMan–Sage integration bridges this, syncing invoice data from PlanMan automatically.
6. Zoho Invoice one of the best free standalone invoicing tools
Zoho.com/uk/invoice – free forever for UK businesses
Zoho Invoice is worth knowing about simply because it is genuinely free and available to UK businesses at no cost. The free plan supports up to 1,000 invoices per year, unlimited clients, VAT invoice creation, automated payment reminders, time tracking, a client portal, and a mobile app for iOS and Android.
Zoho confirmed in 2026 that the free plan also supports the new MTD for Income Tax requirements, which makes it a compliant option for sole traders facing the April 2026 mandate.
Zoho Invoice does not replace accounting software even though it handles invoicing, client billing, and expense tracking. For bank reconciliation, VAT return filing, and year-end accounts you would need Zoho Books (the broader accounting product, which starts at £12/month on the Standard plan) or a separate accounting tool.
For a sole practitioner architect wanting clean, professional invoicing without a monthly subscription, Zoho Invoice is the obvious no-cost starting point.
However, Zoho Invoice is a standalone invoicing tool, not a project management platform. There is no integration with PlanMan, no awareness of RIBA stages or fee proposals, and the client cap on the free tier.
For anything beyond simple one-off invoicing, the Zoho Books paid tier or one of the platforms above is more appropriate.
7. Total Synergy the best AEC-specialist platform for larger practices
Totalsynergy.com – custom pricing (Business and Enterprise plans) – demo required
Total Synergy is a cloud-based practice management platform built specifically for architecture, engineering, and construction firms. The product has been in the market for 25 years and has an established presence in Australia, New Zealand, and the UK.
Where most general accounting tools have to be adapted to fit an AEC workflow, Total Synergy is designed around it from the ground up: stage-based and discipline-based invoicing, WIP visibility, resource planning, timesheet integration that flows directly into billing, and budget tracking against defined project phases.
The invoicing capability is genuinely architecture-oriented. You can send invoices for individual project stages or multiple stages at once, with mixed fee types (fixed fee, percentage complete, time-and-materials) within the same project.
The caveats: Total Synergy does not have a dedicated mobile app (browser-based only), which several users flag as a limitation for site visits and remote working. Pricing is enterprise-oriented and custom, so practices should expect a structured demo and implementation process rather than a self-service trial.
Some user reviews note that reporting can be counter-intuitive and that the platform’s depth requires time to master. It is a more significant operational investment than PlanMan or Xero, and may be more than a small practice needs.
8. GoCardless – best for automating direct debit collection
Gocardless.com – pay-per-transaction from 1% + 20p (capped at £4)
GoCardless is a payment collection platform built around UK direct debit. Rather than waiting for clients to transfer funds when an invoice is due, GoCardless collects payment automatically on the specified date. For practices with recurring clients, retainer arrangements, or structured stage-payment schedules, this removes the single largest source of payment delay: the client who approved the invoice but has not yet got around to paying it.
The combination of stage-linked invoicing in PlanMan and automated direct debit collection via GoCardless is particularly powerful: a stage completes, an invoice is triggered, and payment is collected automatically.
9. Stripe – best for card payments
Stripe.com/gb – 1.5% + 20p per UK card transaction
Stripe is the world’s most widely used payment infrastructure provider.
For architectural practices billing private residential clients or smaller commercial clients who prefer to pay by card rather than bank transfer, it enables direct card payment from an invoice link.
Like GoCardless, Stripe is a payment tool rather than an accounting platform. Used alongside PlanMan’s invoice management and Stripe integration, it turns a stage-completion invoice into something a client can pay immediately.
What to look for in billing software for an architecture practice
If you come across and settle on another product, here is the recap of the main selection criteria:
- Stage-linked invoicing.
- Quote-to-invoice workflow.
- MTD compliance.
- Payment collection integration.
- Multi-project visibility.
- Your accountant’s preference.
The bottom line
Every dedicated accounting platform on our list does invoicing competently. The question is not whether they can produce and send an invoice, because they all can. The question is how much work the practice has to do to connect that invoice to the project it relates to, the fee proposal that preceded it, and the stage completion that triggered it.
For most architectural practices, the answer with Xero, Sage, FreshBooks, FreeAgent, or Zoho is that on their own, they take quite a lot of manual work.
Each of those tools is powerful within its domain, and several have PlanMan integrations that make the accounting side run smoothly when PlanMan handles the project and billing layer.
For the vast majority of UK architecture firms (from sole traders to practices of 20 or 30 people) PlanMan’s built-in invoicing gives the features that matter most for architecture-specific billing, at a price point that includes the rest of the practice management infrastructure in the same subscription.
Start your free 30-day PlanMan trial and see how much cleaner the billing workflow becomes when the invoice comes directly out of the project.