If you ask ten agency owners which accounting software they use, roughly six will say Xero and three will say QuickBooks. The last one is on FreeAgent and mildly smug about it. Both Xero and QuickBooks are genuinely excellent — this is not a case where one is clearly better and the other is a poor choice. But the way agencies bill clients, track project profitability, handle contractors, and integrate software makes some of their differences matter a lot more than they would for a typical product business.
This post is about making a considered choice, not a random one. It covers where each platform genuinely excels for agency use, where each falls short, what the integration picture looks like when you connect either to a CRM or project management tool, and a practical recommendation depending on your situation.
The UK Market Context: Why Most Agencies Land on Xero
Xero’s dominance among UK agencies is not accidental. The platform launched in New Zealand but deliberately targeted the UK market early, and by the time QuickBooks Online (QBO) properly pushed into the UK, Xero had already won the accountancy profession. A large proportion of UK-based accountants and bookkeepers are Xero-certified first, QBO-certified second. When an agency owner asks their accountant what to use, the answer is usually Xero — not because QBO is worse, but because that’s what the accountant is most comfortable advising on.
QuickBooks Online’s UK version is also genuinely good, and Intuit has invested heavily in closing the gap. For agencies with a US component — an American parent company, US-based contractors, billing in USD — QBO often makes more sense because its US edition is the market leader there and cross-border accounting is smoother. For a purely UK agency with a UK accountant, Xero starts with a structural advantage.
That said, “my accountant uses it” is not a good enough reason on its own. The more important question is how each platform fits the actual operational shape of an agency.
How Each Platform Handles Agency Billing Patterns
Agencies have unusual billing patterns compared to most small businesses. You might have a mix of fixed-fee project invoices, monthly retainer invoices that recur automatically, ad hoc expense pass-throughs, milestone-based billing tied to project delivery, and the occasional one-off for work outside scope. Both platforms handle this, but with different levels of friction.
Recurring invoices are where Xero has a clear edge. Its repeating invoice functionality is straightforward and reliable — you set up a schedule, it fires, and it integrates cleanly with your bank feed. Many agencies run 20–40 retainer invoices every month, and having these sent automatically from within the accounting system saves meaningful time. QuickBooks Online has recurring transactions too, but agency owners who have used both consistently describe Xero’s implementation as less fiddly to configure and easier to modify when a retainer amount changes.
Multi-currency is more nuanced. Both platforms support multiple currencies, but it is a paid add-on in Xero (available on the Established plan at £47/mo) and included in QBO’s higher tiers. If you regularly invoice clients in euros or dollars, this pricing difference is worth factoring in. A ten-client agency with three international retainers should price both platforms at the plan level they’d actually need, not the headline starting price.
Project tracking is one area where neither platform is strong enough to use as your primary tool. Xero Projects exists and allows you to track time and costs against a project and produce a basic profitability view. QBO has a Projects module too. Both are functional but limited — they are not a substitute for dedicated project management. The correct architecture for an agency is a proper project management or CRM layer that tracks time, costs, and billing, with a clean sync to your accounting system for the financial records. Trying to do project management inside Xero or QBO leads to workarounds that break down as you grow.
Agency billing checklist
Before choosing, confirm your accounting software handles: recurring monthly retainers, milestone invoicing, expense pass-throughs with markup, partial billing on fixed-fee projects, and credit notes when a retainer client churns mid-month. Both Xero and QBO do all of these — but the UX varies considerably.
Contractors, Expenses, and Subcontractor Costs
Most digital agencies use a mix of employed staff and freelance contractors. The way you manage and reconcile contractor costs differs between the platforms in ways that affect your month-end close time.
Xero’s bill tracking is widely regarded as cleaner for agencies with regular contractor invoices. You can create a contact for each contractor, approve their bills, and reconcile against bank payments in a single workflow. Purchase orders are available on the higher plan tier, which matters if your finance process involves approval steps before committing contractor spend. Aged payables reporting in Xero is clear and easy to share with a finance director or bookkeeper who isn’t logging in daily.
QuickBooks Online’s expenses module is strong if your team submits a lot of reimbursable expenses via receipts — the mobile app is slightly better than Xero’s for snapping receipts on the go, and QBO integrates with more expense management apps in the UK (though Dext, formerly Receipt Bank, works well with both). For agencies where the main contractor cost flow is inbound bills from freelancers rather than employee reimbursements, the practical difference is small.
One area where QBO has a genuine advantage is time tracking and payroll. QuickBooks Payroll is available in the UK and integrates tightly with QBO — if you’re running payroll for employed staff inside your accounting software, QBO’s integrated payroll is more complete than Xero’s equivalent (Xero Payroll exists but has had feature gaps in the UK compared to its Australasia version). If payroll is purely handled outside (via a bureau, or an integrated tool like BrightPay), this difference disappears.
The Integration Question: Connecting Either to Your Agency CRM
This is where the choice gets practically important for an agency running a modern tech stack. If you’re using an agency management platform or CRM to track clients, raise invoices, and manage projects, you need a clean two-way sync with your accounting software — not just a one-way push, and not a manual CSV export.
The core integration flow for an agency looks like this: you raise an invoice in your CRM against a specific client and project, that invoice syncs automatically to your accounting software as a draft or approved invoice, payments reconcile against your bank feed in the accounting tool, and payment status flows back to your CRM so your account manager knows who has and hasn’t paid. Without that last step, you end up with account managers chasing clients who’ve already paid, which is embarrassing and corrosive to trust.
Marque CRM integrates with both Xero and QuickBooks, and the sync covers the full cycle: invoices, credit notes, client records (contacts and companies), and payment status. When an invoice is marked as paid in Xero or QBO, it reflects in Marque within minutes — no manual reconciliation step, no end-of-month spreadsheet to check who owes what. This matters for agencies running 30+ active client relationships where manual payment tracking is genuinely not feasible.
Which integration is more reliable? Both are stable and well-supported. Xero’s API is generally considered more developer-friendly and has a longer track record of third-party integrations, which means the ecosystem of tools that work with Xero tends to be slightly broader. QBO’s API has improved substantially in recent years and the integration coverage is now comparable for most agency use cases. If you’re evaluating a specific piece of software — a CRM, a project tool, a time tracker — check that it supports both before assuming.
Watch out for one-way syncs
Some agency tools advertise “Xero integration” or “QuickBooks integration” but only push invoices one way — from your CRM to your accounting software. Payment status never flows back. Before committing to any CRM or project tool, confirm the integration is bidirectional: invoices out, payment status back in. A one-way sync still saves time but leaves a gap in your billing visibility.
Reporting and Financial Visibility for Agency Owners
The honest answer is that both platforms provide adequate financial reporting for most agencies. Profit and loss, cash flow, aged receivables, VAT returns — both do these competently. The difference is in the detail and the ease of getting to the numbers you actually care about as an agency owner.
Xero’s reporting has become genuinely strong since it was rebuilt a few years ago. The custom report builder allows you to slice your P&L by tracking category — which, for an agency, means you can track profitability by client group, service line, or team if you set your chart of accounts up correctly from the start. Budget versus actuals reports are clean and easy to export. The dashboard gives a clear cash position and outstanding invoice view without needing to run a report.
QuickBooks Online’s reporting is comprehensive and, if anything, has more standard report templates out of the box. The class and location tracking system in QBO serves a similar purpose to Xero’s tracking categories — you can segment your P&L by service line or division. QBO’s cash flow forecast tool is notably better than Xero’s equivalent; it pulls from your bank feed and outstanding invoices to project forward 90 days. For agencies where cash timing is tight — waiting on a large project invoice to clear before paying contractors — this forecast is genuinely useful.
Neither platform gives you the agency-specific metrics that actually matter for operations: utilisation rate, revenue per employee, realisation rate, client profitability by project. Those require a layer above the accounting software — either a dedicated reporting tool, or an agency management platform that pulls from both your project data and your financial data. Connecting Marque CRM’s reporting and utilisation modules to your accounting sync gives you a complete picture: operational metrics in the CRM, financial records in the accounting tool, both drawing from the same source of truth.
Side-by-Side: The Key Differences at a Glance
The Practical Recommendation: Which One to Choose
For most UK digital agencies, Xero is the better default. The accountant ecosystem advantage is real and underrated — having your bookkeeper or accountant working fluently in the same software you use means month-end closes faster, queries get answered sooner, and you spend less time explaining your chart of accounts to someone who primarily works in a different tool. If your accountant is Xero-certified and your agency is UK-only, Xero is the right choice for the majority of agencies under £2m revenue.
Choose QuickBooks Online if: your agency bills a significant share of clients in USD or works with US-based parent companies; you want integrated payroll and prefer to keep it inside your accounting software; your bookkeeper or management accountant specifically prefers QBO; or you want a better built-in cash flow forecast and your agency is at a stage where cash timing is a frequent concern.
If you’re on FreeAgent — common among sole traders and very early-stage agencies — both Xero and QBO are worth migrating to once you have more than three or four staff. FreeAgent is excellent for a freelancer billing straightforward retainers, but its reporting and contractor management capabilities start to show limits as complexity grows.
One thing worth emphasising: the accounting software you choose matters less than the integration layer around it. An agency running Xero with invoices raised manually and emailed as PDFs, with payment reconciliation done at month-end by a bookkeeper, has a worse financial operation than an agency on QuickBooks with a proper CRM integration pushing invoices automatically and surfacing payment status in real time. The platform choice is secondary to the workflow design.
Marque CRM’s accounting integrations support both Xero and QuickBooks on the Agency plan, meaning you can connect either and get the same clean sync behaviour. The integration handles invoice creation, contact syncing, credit notes, and payment status callbacks — so whichever platform you choose, the operational workflow is the same.
Switching Platforms: What Migration Actually Involves
If you’re already on one platform and considering switching, the honest answer is that migration is a meaningful project and not something to do casually mid-year. A typical mid-year migration for a 10-person agency involves exporting your chart of accounts, historical transactions, and client contacts; mapping them to the new platform’s structure; re-setting up bank feeds; and re-creating any recurring invoices. Your accountant will also need to update their access. Budget two to three days of proper attention from whoever manages your finances, plus a month of parallel running to catch anything that doesn’t transfer cleanly.
The practical implication is that if you’re starting fresh — a new agency, or one that’s currently on spreadsheets or FreeAgent — this is the moment to choose the right platform and set it up properly. Once you have three years of history in Xero, the migration cost to QBO becomes harder to justify unless you have a strong operational reason.
If you’re setting up your accounting integration with a CRM for the first time, make sure the CRM you choose supports both platforms before you commit. Locking yourself into a CRM that only integrates with one accounting package removes future optionality — and agency tech stacks evolve over time as the business grows.
The Bottom Line
Xero and QuickBooks Online are both capable, modern accounting platforms that handle everything a UK digital agency needs. Xero wins on ecosystem and accountant adoption in the UK. QuickBooks wins on payroll and cash flow forecasting. For most agencies, the choice comes down to what your accountant prefers and whether you have a multi-currency or US operations angle.
What matters more than the platform choice is closing the loop between where you manage clients and projects and where your financial records live. Manual invoice entry, spreadsheet reconciliations, and month-end data-entry sessions are where small agencies lose time and money — not in the choice between two solid cloud accounting tools. An integrated CRM that pushes invoices automatically and pulls payment status back gives you that loop, regardless of which side of the Xero/QuickBooks divide you sit on.
If you’re evaluating agency management platforms and want to understand how the accounting integration works in practice, Marque’s Agency plan includes both Xero and QuickBooks integrations — and there’s a 90-day trial with no credit card required.