Batch Invoicing: How to Send Multiple Invoices at Once

Batch invoicing means preparing or sending many client invoices in one working session, often at month-end for service businesses or after a production run for product companies. Done well, it saves context switching. Done carelessly, it repeats the same error across many clients at once.

A fixed cutoff (the same close date each month) is the foundation: everyone knows which work goes on this month's invoices and which rolls to the next.

When batching makes sense

Monthly close

Consultancies, agencies and freelancers often invoice on the last business day of the month or the first day of the next. Everyone on the team knows the deadline.

After a shared event

Training cohorts, conference sponsorships or bulk licence sales: one campaign, many similar invoices.

After timesheet approval

Once managers approve timesheets, finance prepares all hourly invoices in one pass. See hourly vs fixed pricing models.

How to run a month-end batch, step by step

Step 1: Sort clients into templated and variable

Recurring retainer clients with predictable scope are easy to template. Project-based clients with variable scope are harder. Group the two separately, because they need different amounts of checking.

Step 2: Keep a starting invoice for each recurring client

For each retainer client, keep a standard invoice with the usual line items, terms and PO number. In InvoiceQuickly you can duplicate the previous invoice on any plan, change the period and amounts, and send it. For fixed amounts, a recurring schedule can create the invoice for you; keep the first few as drafts for review before you let them send automatically.

Step 3: Freeze the data at the cutoff

On the cutoff date, stop adding hours or costs to this month's invoices. Anything later rolls to the next cycle. If managers approve timesheets, wait for approval before you start.

Step 4: Run the pre-flight checks

Check one invoice thoroughly first, because an error in the template repeats on every invoice. Then check the batch:

Rates: promotional or old rates haven't carried over.
Tax and currency: the rules for each client's jurisdiction, via invoice tax compliance and foreign-currency invoicing where relevant. Spot-check tax lines on random invoices; one wrong rate can repeat across dozens.
Supporting references: SOW references, PO numbers or timesheet backups, included the same way on every invoice.
Numbering: every invoice has a unique number from one controlled sequence, and any gap has a reason you can show (for example a voided draft). UK and EU VAT invoices need a sequential number; see invoice number best practices.
Contacts: billing email addresses are current. A typo in a domain sends a client's invoice to a stranger.

When a batch is bigger than one person can check carefully, ask a second person to review it.

Step 5: Send in a controlled way

If you email a large batch from your own mailbox at once, some messages may be delayed or filtered. Send from an invoicing tool or a transactional email service, or spread sends out, and watch for bounces. Keep a send list as you go, so if sending stops part-way you resume from the list and nothing goes twice. Even from a template, add one sentence about what period the invoice covers; it cuts "what is this?" replies. Templates are in how to send an invoice by email.

Step 6: Reconcile the same day and schedule follow-ups

Compare the batch total with your accounts receivable the same day, and note the batch date and invoice number range in your audit trail. If a client received a duplicate, send a one-line correction before they pay twice. Plan reminders at send time so you don't chase each invoice from memory: on InvoiceQuickly Pro, scheduled reminders go out before and after the due date, and the free payment reminder templates give you a gentle, firm and final version if you send them by hand. Log corrections and client rejections per batch: the same PO error twice means a template fix, not more care.

Batching vs recurring and subscription billing

Recurring schedules handle repeating amounts; batching handles variable month-end totals. Many businesses use both: recurring for flat retainers, a batch for hourly true-ups. These are illustrative starting points, not benchmarks:

Scenario	Volume	Typical approach
Solo freelancer with a handful of clients	Low	One by one, from a duplicate of last month's invoice
Small agency with 8 retainer clients	Low to medium	A batch on the 1st, each invoice duplicated from last month's, so the work is checking period, hours and amount
Agency with dozens of monthly clients	Medium	Recurring schedules for retainers plus a reviewed month-end batch
Subscription business or membership site	High	Subscription billing that charges saved payment methods, sends renewal notices and retries failures
Marketplace paying many sellers	Very high	Custom integration with a payment provider, a reconciliation report each cycle and manual review of exceptions

The more invoices you send and the more alike they are, the more a recurring or subscription tool pays off.

Batch invoicing in InvoiceQuickly

What you can do today:

Duplicate an invoice (all plans) to start next month's invoice from last month's.
Draft invoices from a description by typing or speaking what you did; you review each draft before saving (Free: 3 AI drafts; Pro: unlimited).
Recurring schedules (Pro): weekly, monthly, quarterly or yearly schedules that create invoices as drafts for review or send them automatically. The in-app schedule has one line item with saved tax, discount, currency, notes and payment terms. You can pause or resume a schedule, but not edit it after you create it.
Email delivery and scheduled reminders (Pro).
Payment links (Pro) through your own Stripe or PayPal account; the payment is recorded when the provider confirms it.
CSV export (Pro) to check a batch against your books. It includes estimate and credit note rows and has no balance column, so filter by the INV- prefix and check payments separately.
Bill tracked time and expenses (Pro): select a client's unbilled time and expenses into one draft invoice that you review before sending.
Public API (paid plans, with an API key you create): create clients and draft invoices from another system. Drafts are never sent from there. A Zapier app is available by private invitation while Zapier's public review is pending; it is not a public Zapier listing.

What it doesn't do: there is no bulk invoice creation or bulk send in the app, and no import of invoices or clients from a spreadsheet. Invoices created through the API arrive as drafts, so each one is still reviewed and sent on its own. If you invoice dozens of variable-amount clients every month and need to create or send them in one action, InvoiceQuickly is not the right fit for that part of your workflow.

See what's on Pro.

Frequently asked questions

When should I start batching?

When invoicing starts to take a noticeable block of time each month, or when several invoices go out on the same date anyway. For a handful of invoices, creating each one individually is fine.

Should I batch project invoices?

Usually not. Project invoices are different each time. Batching works best for similar or recurring billing.

How do I handle client-specific customizations?

Keep a starting invoice per client with their usual lines, terms and PO number, and duplicate it each month. In InvoiceQuickly, your logo, brand colour and PDF style apply to all invoices (Pro), so per-client differences go in the line items, notes and terms.

What if my batch fails to send?

Check which invoices went out (your send list or the delivery status in your tool), resend the ones that failed, and contact any client whose address bounced. Don't resend the whole batch, or clients will get duplicates.

Are batch invoices more vulnerable to errors?

They can be, because a template error repeats on every invoice. Check one invoice thoroughly before you prepare the rest, then spot-check the batch before sending.