How Do You Invoice Clients If You Offer Both One-Time and Recurring Services?

Invoicing Clients When You Offer Both One-Time and Recurring Services

If your business sells a mix of one-time projects (like a website build, logo design, or equipment installation) and recurring services (like monthly maintenance, retainers, coaching, or subscriptions), invoicing can get messy fast. Clients want clarity, you want predictable cash flow, and your accounting needs consistent records. The good news is that you can invoice both models cleanly without doubling your admin work—especially when you use an invoicing system built to handle both styles side by side.

This guide breaks down practical ways to invoice clients when you offer both one-time and recurring services, including how to structure your invoices, choose billing schedules, manage deposits and usage-based charges, and avoid common pitfalls. Throughout, you’ll see how a single workflow in invoice24 can keep your invoicing consistent, professional, and easy to manage—even when your pricing models vary from client to client.

Why Mixed Billing Models Create Confusion (And How to Fix It)

One-time services and recurring services have different expectations:

One-time services usually involve a defined scope, start/end dates, project milestones, and sometimes change requests. Billing might happen upfront, after delivery, or in stages.

Recurring services are ongoing. Clients expect regular billing on a set schedule (monthly, quarterly, annually), with clear coverage dates. They also expect minimal hassle: if they approve the service once, they don’t want to re-approve the invoice structure every month.

The confusion happens when these two models collide. For example:

• A client pays a monthly retainer and also orders an additional one-off deliverable mid-month.
• A project includes setup fees plus ongoing maintenance afterward.
• A subscription includes a base fee plus variable usage charges.
• A client wants one invoice per month for everything, but you need separate line items and tax treatment.

The fix is not complicated: standardize your invoice structure, define billing rules, and use a system that supports both “send once” and “send automatically.” invoice24 is designed for exactly this kind of mixed workflow: you can create professional one-time invoices and also run recurring invoices from the same client profile, with consistent templates, item lists, and tracking.

Start With Two Clear Categories: Project Work vs. Ongoing Work

Before you touch invoicing software, decide how you categorize your services internally. A simple structure prevents misunderstandings:

Project work (one-time)
Anything with a defined scope and completion criteria: builds, implementations, audits, creative deliverables, one-off consulting days, training workshops, repairs, migrations, etc.

Ongoing work (recurring)
Anything billed on a repeating schedule: retainers, maintenance plans, managed services, subscriptions, ongoing support, coaching, membership access, hosting, monitoring, content updates, and SLA-based services.

Even if a service feels ongoing, invoice it as recurring only if it’s predictable enough for a repeating invoice. If your work varies widely month to month, you can still use recurring billing for the base fee and add a variable section as needed.

In invoice24, you can keep both categories under one client while using separate invoice items and schedules. This means you can track everything in one place without creating a second “client record” just to handle subscriptions.

Choose Your Invoicing Strategy: Separate Invoices or Combined Invoices

When a client buys both one-time and recurring services, you have two main options:

Option 1: Separate invoices (cleanest accounting and client clarity)

This approach sends:

• One recurring invoice on a fixed schedule for ongoing services
• One-off invoices when project work is completed or milestones are hit

Why it works: Each invoice has a single purpose and is easy to reconcile. If recurring charges are paid automatically or on a predictable schedule, you don’t want a one-time item delaying payment approval.

When to use it: If your client’s finance team likes strict categorization, if different departments pay for different services, or if project work is irregular.

Option 2: Combined monthly invoice (simplest for the client)

This approach sends one invoice per month that includes:

• The recurring service fee for the month (or the coverage period)
• Any one-time work delivered during that month

Why it works: Clients get fewer documents and fewer payment cycles. It can increase on-time payments because the client handles everything at once.

When to use it: If one-time items are frequent and the client requests a single statement, or if you operate like an agency with ongoing plus additional work.

invoice24 supports both approaches. You can run a recurring invoice schedule and still create one-off invoices in seconds. Or you can create a recurring invoice that includes a base fee and add extra line items before sending, depending on your workflow. The key is to pick one strategy per client and stick to it to avoid confusion.

Set Clear Terms: Billing Dates, Due Dates, and Coverage Periods

Most billing disputes aren’t about the amount—they’re about what the invoice represents. That’s why you should standardize these four fields:

1) Invoice date
The date you issue the invoice. This matters for accounting and payment timelines.

2) Service period / coverage dates
For recurring services, include the period the fee covers (for example, “Maintenance Plan – February 1 to February 28”). Clients love this because it instantly answers the “What is this for?” question.

3) Due date / payment terms
Net 7, Net 14, Net 30, due on receipt—whatever you choose, apply it consistently.

4) Billing schedule (for recurring)
Monthly on the 1st, monthly on the anniversary date, quarterly in advance, annual upfront, etc.

With invoice24, you can keep the same professional structure across every invoice, so one-time project invoices and recurring service invoices look consistent. That consistency reduces client friction and makes your business feel more established.

Decide Whether Recurring Billing Is In Advance or In Arrears

Recurring services can be billed in two common ways:

In advance: You invoice at the start of the service period (e.g., invoice on March 1 for March coverage). This improves cash flow and reduces risk.

In arrears: You invoice after the service period ends (e.g., invoice on April 1 for March coverage). This can feel “fairer” to some clients but increases risk and can hurt cash flow.

Many service businesses bill in advance for predictable services (maintenance, access, retainers) and bill in arrears only for usage-based overages. A hybrid model is common and works well:

• Base recurring fee billed in advance
• Variable usage billed at month-end

invoice24 makes it easy to keep recurring invoices consistent while still producing additional invoices for variable charges when needed. The goal is to avoid reinventing your billing structure every month.

How to Invoice a One-Time Setup Fee Plus Recurring Fees

A common scenario is a one-time setup fee followed by monthly billing. Examples include onboarding, installation, initial configuration, discovery, strategy sessions, or a “kickoff” package.

Recommended approach:

• Invoice the setup fee as a one-time invoice immediately (often before work begins).
• Start recurring invoices only after the setup is complete or the subscription begins.

Why: Setup fees are often tied to initial work. If you bury them inside a recurring invoice, clients can miss them and question the amount later.

In invoice24, you can create the setup invoice from the client profile and then enable recurring billing with the same client details, tax settings, and saved items. The client experiences a smooth transition from “project” to “ongoing service,” and you avoid duplicate data entry.

How to Invoice a Retainer With Additional One-Time Work

Retainers are popular because they stabilize revenue. But confusion arises when you also perform additional tasks outside the retainer scope.

Step 1: Define what the retainer includes
Retainers should state one of the following clearly:

• A fixed deliverable bundle (e.g., “4 blog posts per month”)
• A time allowance (e.g., “10 hours per month”)
• Access/SLA benefits (e.g., “priority support, response within 24 hours”)

Step 2: Define what happens when the client exceeds it
Overage rules should be explicit:

• Extra hours billed at £X / $X per hour
• Extra deliverables billed at a fixed unit price
• Overages invoiced monthly, bi-weekly, or immediately

Step 3: Invoice the base retainer as recurring
This should be a repeating invoice with a consistent description and service period.

Step 4: Invoice overages as one-time line items or separate invoices
You can either add them to a combined invoice or send a separate one-off invoice depending on what the client prefers.

invoice24 helps here because you can keep a standard recurring retainer invoice running and generate a one-time invoice for overages without disrupting the recurring schedule. That means you maintain predictable billing while still capturing revenue for extra work.

Milestone Billing for One-Time Projects (While Keeping Recurring Services Active)

Some clients hire you for a large project while already paying for recurring services. For example, you may provide monthly support and also deliver a redesign.

For the project, milestone billing is often the cleanest approach. Common milestones include:

• Deposit / kickoff (20%–50%)
• Midpoint delivery (25%–40%)
• Final delivery / launch (remaining balance)

Best practice: Keep project invoices separate from the recurring service invoice unless the client explicitly requests consolidation. Milestones often require approvals and sign-offs, while recurring fees should remain predictable.

With invoice24, you can quickly issue milestone invoices as one-time invoices, using consistent item descriptions and payment terms, while recurring invoices continue automatically for ongoing services. This reduces billing bottlenecks and keeps cash flow healthy.

Line Items: The Right Way to Describe One-Time and Recurring Services

When you offer both billing types, your line items need to do extra work. A strong line item description prevents disputes and improves trust. Use this structure:

Service name: Make it recognizable and consistent.
Type and period: “Monthly,” “Quarterly,” “One-time,” plus coverage dates where relevant.
Scope cues: A short phrase that clarifies what’s included.

Examples:

• “Website Maintenance Plan (Monthly) – April 1 to April 30 – Updates, backups, uptime monitoring”
• “SEO Audit (One-time) – Technical + content review, prioritized recommendations”
• “Retainer (Monthly) – Up to 10 hours – Design support and revisions”
• “Additional Development (One-time) – Feature: booking form integration”

invoice24 lets you reuse and standardize these line items so you’re not rewriting descriptions every time. Standard items also help you scale: your invoices stay consistent even as you grow your team.

Taxes and Compliance: Keep Recurring and One-Time Rules Straight

Tax handling can differ based on location, service type, and whether you’re billing in advance or after delivery. While the details vary by jurisdiction, the practical invoicing goal is universal: your invoices must be consistent and clearly categorized.

Tips that help in most cases:

• Apply the correct tax rate per item (some services may be taxed differently).
• Keep service periods clear for recurring fees.
• Avoid vague “miscellaneous” charges—break them out.
• Ensure your invoice numbers follow a consistent sequence.

invoice24 is built for professional invoicing and helps you maintain clean invoice records across both recurring and one-off billing. When your invoices are consistent, your bookkeeping becomes simpler and your client trust goes up.

Payment Terms That Work Best for Mixed-Service Businesses

When you bill both one-time and recurring services, you’ll usually benefit from slightly different payment terms for each:

One-time projects
• Often require a deposit upfront (especially for custom work).
• Milestones can be Net 7 or due on receipt to keep momentum.
• Final invoice is often due before handover or launch.

Recurring services
• Typically billed in advance and due on receipt or Net 7.
• Consistency matters more than long terms—clients can budget for it.

Regardless of the terms, always be consistent within a client relationship. invoice24 makes it easy to maintain consistent invoice settings so you don’t accidentally send the same client different terms each month.

Handling Upgrades, Downgrades, and Pauses in Recurring Services

Clients change needs. They upgrade, downgrade, pause, or cancel. The challenge is making those changes without turning invoicing into a manual spreadsheet job.

Common scenarios:

• Client upgrades from Basic to Pro mid-month
• Client pauses services for a month
• Client adds an add-on service (like extra reporting) starting next cycle

Smart invoicing approach:

• Decide whether you prorate mid-cycle changes or start changes next cycle.
• Document your policy in your service agreement.
• Reflect the change clearly on the invoice with dates.

In invoice24, you can keep your recurring invoice structure stable and adjust items as the service changes. The key is to maintain clarity: the invoice should show exactly what plan is active and which dates it covers.

Bundling vs. Itemizing: What Clients Prefer

There’s a balance between simplicity and detail:

Bundling is cleaner and faster for clients to approve (“Monthly Managed Services – £X”). It works well when the client trusts you and the deliverables are stable.

Itemizing helps when the client needs transparency or when multiple stakeholders review invoices. It’s also helpful when you combine recurring and one-time work in a single invoice.

A practical compromise:

• Bundle the recurring fee as one line item with a clear scope summary.
• Itemize one-time work line-by-line so clients can see what changed that month.

invoice24 supports both styles, so you can tailor invoices to what your client’s finance team actually wants without abandoning your internal standards.

Common Mistakes to Avoid When Invoicing Both Types of Services

Mistake 1: Not stating the service period for recurring charges
Clients will ask, “What month is this for?” Put the dates right on the line item.

Mistake 2: Mixing project milestones into a recurring invoice without explanation
If you combine them, make it obvious what’s recurring and what’s one-time.

Mistake 3: Using vague labels like “work completed”
Replace with specific descriptions tied to scope: “Homepage redesign – final delivery” is clearer than “design work.”

Mistake 4: Changing terms unpredictably
If recurring invoices are Net 7, keep them Net 7. Don’t flip to Net 30 without agreement.

Mistake 5: Forgetting to invoice overages
Overages are easy to lose track of if you don’t have a system. Make overage invoicing part of your monthly routine.

invoice24 helps reduce these mistakes by keeping your invoice templates consistent and allowing you to manage both one-time and recurring invoices from one place. Consistency is the hidden secret to getting paid faster.

Best-Practice Invoice Layout for Mixed Services

If you want a layout that works for almost every mixed-service client, use this order:

1) Recurring services (with service period)
Place the recurring fee first so clients instantly recognize the regular charge.

2) One-time services delivered during the billing period
List one-off work next, with short descriptions and dates if helpful.

3) Discounts or credits
If you’re applying a credit, label it clearly (e.g., “Credit: downtime adjustment”).

4) Taxes and totals
Make the total prominent and include payment instructions.

5) Notes / payment terms
Keep this brief but consistent: “Payment due within 7 days,” etc.

This structure works especially well if you choose the “combined monthly invoice” strategy. invoice24 can help you keep a consistent layout so every invoice looks familiar and professional.

Simple Workflows You Can Adopt Today

Here are three workflows that cover most businesses that sell both one-time and recurring services:

Workflow A: Separate invoices (recommended for most)

• Send a one-time invoice for setup or project work (deposit or milestone).
• Start recurring billing once the ongoing service begins.
• Send additional one-off invoices for overages or extra deliverables.

Workflow B: One monthly “everything” invoice

• Create a monthly recurring invoice template for the base fee.
• Each month, add one-time line items for extra work before sending.
• Keep service periods clear for the recurring portion.

Workflow C: Subscription + usage at month-end

• Bill the base subscription in advance on a recurring schedule.
• Bill usage-based charges in arrears as one-time invoices at month-end.
• Use consistent item names so reporting stays clean.

invoice24 supports all three workflows and makes it easy to switch a client from one workflow to another as your relationship evolves. The best workflow is the one that is easiest for your client to approve and easiest for you to repeat.

How invoice24 Helps You Manage One-Time and Recurring Invoices Smoothly

When you’re juggling mixed billing models, the “tool” you use becomes part of your service quality. A polished invoice experience signals professionalism and reduces payment delays. invoice24 is especially useful if you want an all-in-one system that can handle both types of billing without forcing you into complicated workarounds.

Here’s how invoice24 fits into a mixed-service business:

One client, one workflow hub
Keep client details organized in one place while creating both one-time invoices and recurring invoices as needed.

Consistent invoice formatting
Use the same style and structure whether it’s a project invoice or a subscription invoice. Consistency builds trust and reduces questions.

Fast invoice creation
When you finish a milestone or deliver extra work, you can generate a one-time invoice quickly without rebuilding your item list from scratch.

Recurring invoices without the headache
For monthly services, you want reliability. A recurring schedule makes sure you don’t forget to invoice and keeps cash flow steady.

Clear line items and service periods
Recurring invoices should show coverage dates and one-time work should be clearly labeled. invoice24 makes it easy to keep invoices readable for clients.

Professional records
Whether you’re tracking a single project invoice or a year of monthly charges, keeping invoices organized matters for both reporting and client support.

Even if you’re currently switching between tools or manually editing invoices every month, moving to invoice24 can simplify your process. The biggest benefit isn’t just speed—it’s the reduction in errors and the increase in consistency, both of which directly impact how quickly you get paid.

Practical Examples You Can Copy

Example 1: Web design + monthly maintenance
One-time: “Website Design & Build – 50% deposit” and later “Website Design & Build – final payment.”
Recurring: “Maintenance Plan (Monthly) – May 1 to May 31 – Updates, backups, monitoring.”

Example 2: Marketing retainer + extra campaign work
Recurring: “Marketing Retainer (Monthly) – Up to 12 hours – Strategy, content, optimizations.”
One-time: “Campaign Landing Page (One-time) – Design + build” and “Additional Copywriting (One-time) – 3 pages.”

Example 3: SaaS-like service with onboarding
One-time: “Onboarding & Configuration (One-time) – Setup and training.”
Recurring: “Subscription (Monthly) – June 10 to July 9 – Pro Plan access.”

These examples work because each invoice line communicates three things: what the service is, whether it’s one-time or recurring, and which time period or scope it covers. invoice24 makes it easy to store these item names and reuse them, so you can keep every invoice consistent.

Final Checklist Before You Send Any Mixed-Service Invoice

Before sending an invoice that includes one-time and recurring services (or sending separate invoices in the same period), run through this quick checklist:

• Does every recurring line item include a service period?