What finance tools email marketing agencies need to automate billing and ROI

Key takeaways

• Your core stack needs three parts: accounting software (like Xero), a time-tracking and project management tool, and a payments platform. These connect to automate your most repetitive financial tasks.
• Integrating your email service provider (like Klaviyo) is non-negotiable. This link is what turns campaign data into clear client ROI reports and justifies your fees.
• Automation saves 10-15 hours of admin per month for a small team. The goal is to eliminate manual data entry between your project, billing, and accounting systems.
• The right software stack gives you a live profit margin for every client. You see exactly which retainers are profitable after accounting for platform costs and team time.
• Choosing between Xero vs QuickBooks depends on your preferred app integrations. Xero often has deeper connections with agency-specific tools, but both are powerful.

What is a finance software stack for an email marketing agency?

A finance software stack is the set of connected tools you use to run your agency's money. For an email marketing agency, this isn't just accounting software. It's the system that links your campaign work in Klaviyo or Mailchimp to your time tracking, then automatically creates invoices and shows you profit.

Think of it as your financial central nervous system. Every part talks to another. When your designer logs time on a client's email template, that cost flows into the job report. When a campaign generates revenue for the client, that data can feed into their ROI dashboard.

Without a connected stack, you're manually copying numbers from one spreadsheet to another. This wastes time and creates errors. A proper email marketing agency finance software stack automates this flow, giving you accurate, real-time financial pictures.

Why do email marketing agencies need a specialised software stack?

Email marketing agencies have unique financial workflows that generic business software doesn't handle well. You deal with client ad spend, platform fees, and need to prove ROI based on opens, clicks, and sales. A specialised stack automates these specific tasks.

Your biggest cost is people's time. You need to know exactly how much time a £2,000 per month retainer actually consumes. If your team spends 30 hours on it, your profit is gone. A good stack tracks this automatically, so you can price correctly.

You also bill in different ways. Some clients are on retainers, some are project-based, and some have fees tied to performance. Manually calculating these invoices each month is a headache. The right software stack calculates and sends them for you.

Finally, your value is tied to client results. A basic accounting system shows you sent an invoice for £5,000. A connected email marketing agency finance software stack can show that £5,000 helped the client generate £50,000 in sales, making your fee an easy justification.

What are the core components of an email marketing agency finance software stack?

The foundation has three core parts: accounting software, operational tools, and payment systems. These components must work together through app integrations to create a seamless workflow.

First, you need accounting software. This is your system of record. It's where all money in and out is tracked. For agencies, this is typically Xero or QuickBooks. The choice in the Xero vs QuickBooks debate often comes down to which one connects best to your other tools.

Second, you need operational tools. This includes time tracking (like Harvest or Clockify), project management (like Asana or Trello), and CRM (like HubSpot or Pipedrive). These tools capture the cost of delivering your service—your team's time.

Third, you need a way to get paid. Use a payment gateway like Stripe or GoCardless that connects to your accounting software. This means when you send an invoice from Xero, the client can pay online, and the payment is automatically recorded. No manual banking.

The magic happens when these components connect. Your team tracks time in Harvest. At the end of the month, Harvest sends the billable hours to Xero. Xero creates the invoice, sends it to the client via email, and includes a "Pay Now" link via Stripe. This is workflow automation in action.

How do you choose between Xero vs QuickBooks for an email marketing agency?

Both Xero and QuickBooks are excellent cloud accounting platforms. The best choice for your email marketing agency depends on which one offers the smoothest app integrations with the other tools you use or plan to use.

Xero is often favoured by service businesses and agencies. It has a strong ecosystem of integrations with time-tracking and project management tools popular in the agency world. Setting up automated invoice rules based on tracked time is very straightforward in Xero.

QuickBooks is powerful and widely used. Its strength can be in more complex inventory or product-based business reporting. For a pure service agency, both are capable. You should test the connections each one has to your email marketing platforms and project tools.

In our experience working with email marketing agencies, we see more using Xero. The dashboard gives a clear view of cash flow, outstanding invoices, and profit margins, which are the key metrics you need daily. The mobile app is also robust for checking finances on the go.

Ultimately, you can't go wrong with either. The critical step is to ensure your chosen accounting software acts as the central hub for your entire email marketing agency finance software stack. All other apps should feed data into it automatically.

Which app integrations are essential for automating billing?

To automate billing, you need integrations that connect time tracking and project data directly to your invoicing system. The goal is to go from completed work to a sent invoice without touching a spreadsheet.

The first essential integration is between your time-tracking tool and your accounting software. Tools like Harvest, Toggl Track, or Clockify can push timesheets directly to Xero or QuickBooks. This creates draft invoices based on billable hours, which you can review and send.

The second key link is between your project management tool and your time tracker. When your team creates a task in Asana for "Q3 Newsletter Design," they should be able to start a timer from that same task. This ensures time is logged to the right client and project from the start.

For retainer billing, you need an integration that handles recurring invoices. Both Xero and QuickBooks can create automatic invoices for fixed monthly fees. For more complex retainers with variable hours, use a tool like Accelo or Plutio that calculates the variable amount and then syncs the invoice to your accounting system.

These app integrations turn a multi-hour monthly chore into a 15-minute review process. The system does the heavy lifting of collating time, applying rates, and generating invoices. You just check the numbers and hit send.

How can you automate ROI tracking and reporting for clients?

Automating ROI reporting requires connecting your email marketing platform to your reporting dashboard. This proves your value by showing clients the direct revenue impact of your campaigns.

Start with your email service provider (ESP). Platforms like Klaviyo, Mailchimp, and Omnisend have APIs that allow data to be pulled out. You can connect these to business intelligence tools like Google Data Studio (now Looker Studio), Power BI, or agency-specific dashboards like AgencyAnalytics.

Set up a dashboard that pulls in key metrics automatically: open rates, click-through rates, conversion rates, and most importantly, revenue attributed to email campaigns. This dashboard should update daily or weekly without you manually exporting CSV files.

For the highest level of automation, connect this campaign revenue data back to your accounting or practice management software. Some advanced tools allow you to tag client invoices with the revenue they helped generate. This lets you produce a report showing, "Our fee was £3,000. The campaigns we managed generated £45,000 in client revenue."

This automated reporting is a powerful tool for retention and growth. It turns your finance stack from a back-office cost centre into a frontline sales and client service asset. Specialist accountants for email marketing agencies can advise on setting up these metric-driven reporting frameworks.

What does workflow automation look like in practice?

Workflow automation is the sequence of triggered actions that move a financial task from start to finish without manual intervention. For an email marketing agency, a common automated workflow is the monthly client billing cycle.

Here's a real example. Your account manager marks a project as "Ready to Bill" in your project management tool. This action triggers two things. First, it notifies the finance system to collect all tracked time and expenses for that client. Second, it creates a draft invoice in your accounting software with all line items populated.

The system applies the agreed client rate (hourly or fixed fee) and adds any platform costs you've incurred on their behalf, like Klaviyo credits. It then sends this draft invoice to you for a quick review. You approve it, and the system emails it to the client with a payment link.

When the client pays via the online link, the payment is automatically matched to the invoice in your accounting software. The system then marks the invoice as paid and updates your cash flow forecast. If the payment is late, the system can automatically send a polite reminder email.

This entire workflow automation happens with maybe two clicks from you: marking the project billable and approving the invoice. What used to take hours now takes minutes. This is the power of a well-built email marketing agency finance software stack.

How should you track platform and ad spend costs for clients?

You need a system to track, bill, and reconcile every pound spent on email marketing platforms and advertising on behalf of clients. This is often where agency margins get squeezed if not managed tightly.

Use a dedicated tool or method for tracking client expenses. In Xero, you can use the "Repeating Bills" feature for fixed monthly costs like a Klaviyo plan. When the bill comes in from Klaviyo, you code it to a specific client job. The system can then automatically add this cost plus your markup to the client's next invoice.

For variable ad spend (like Facebook ads promoting an email sign-up), use a prepaid system or clear terms. The best practice is to have clients fund a dedicated ad spend account upfront. You then spend from that pool. Your software stack should track this spend in real time and provide clients with transparent reports.

Tools like Float for cash flow forecasting can integrate with Xero to show upcoming platform bill payments. This helps you ensure you always have enough cash to cover these costs before you get reimbursed by the client.

Accurate tracking here does two things. It protects your cash flow, as you're not floating client costs for weeks. And it builds immense trust, as clients can see exactly where their money is going. This level of transparency is a competitive advantage.

What metrics should your software stack help you monitor?

Your finance software stack should give you instant visibility on the metrics that determine agency health. These are not just accounting numbers, but commercial indicators of performance.

First, track gross margin per client. This is your revenue minus the direct cost of delivering the work (team time and platform costs). Your stack should calculate this automatically. Aim for a gross margin of 50-60% on each client. If a client is below 40%, you need to re-price or re-scope.

Second, monitor utilisation rate. This is the percentage of your team's paid time that is billable to clients. Good agencies aim for 70-80% utilisation. Your time-tracking software should show this in real time, so you can see if you're over or under-servicing clients.

Third, watch your cash conversion cycle. How many days does it take from doing the work to getting paid? Your stack should show your average "debtor days." For email marketing agencies, keeping this under 30 days is crucial for smooth cash flow.

Finally, track client lifetime value (LTV) and client acquisition cost (CAC). While these are marketing metrics, your CRM and accounting software can work together to calculate them. You need to know if it costs you more to win a client than you'll earn from them. A connected stack provides these insights.

For a deeper dive into financial planning, try our Agency Profit Score — a free 5-minute scorecard that reveals exactly where your agency stands financially across profit visibility, cash flow, revenue pipeline, operations, and AI readiness.

How do you implement and build your finance software stack?

Start with your accounting software as the central hub. Get this set up correctly first, with your chart of accounts tailored for agency services. Then, add one integration at a time, focusing on the biggest pain point.

If manual invoicing is your biggest time sink, integrate time tracking first. Connect Harvest to Xero and get your team logging all time. Once that workflow is smooth, tackle the next bottleneck. Maybe it's expense tracking or ROI reporting.

Don't try to build the entire email marketing agency finance software stack in one weekend. You'll overwhelm your team. Phase the implementation. A common sequence is: 1) Accounting core (Xero/QuickBooks), 2) Time tracking integration, 3) Payment gateway, 4) ESP data connection for reporting.

Invest in training. A tool is only as good as the people using it. Ensure everyone on your team understands why they need to track time and how to use the project management system. Their compliance is what makes the automation work.

Consider getting professional help. Setting up these systems correctly from the start saves costly re-work later. A specialist who understands agency workflows can configure your stack to match how you actually work, not how a generic business operates.

Building a robust stack is an investment. But the return in saved time, improved cash flow, and better decision-making is immense. It transforms finance from a reactive chore into a proactive strategic function. If you're ready to build yours, take our free Agency Profit Score to get a personalised snapshot of your financial health and see where to focus first.