How to Create Bulk Invoices from Excel

Generating Bulk Invoices from a Spreadsheet

Creating invoices one at a time is tedious when you have dozens or hundreds of clients. With Mergram, you can take an Excel spreadsheet of invoice data, map it to a PDF template, and generate every invoice in a single operation — each one personalized with the correct client details, amounts, and invoice numbers.

Prerequisites

Before you start, make sure you have:

• An invoice PDF template — a designed invoice layout saved as PDF, with space for variable data
• An Excel or CSV file with your invoice data organized in columns and rows
• A Mergram account with credits for the number of invoices you need

Preparing Your Invoice Data

Organize your spreadsheet with one row per invoice. Here is a recommended column structure:

Designing Your Invoice Template

Layout Structure

A typical invoice template has these sections:

Placing Fields on the Canvas

For each column in your spreadsheet, drag it onto the canvas in the corresponding position:

1. Invoice number — Place in the top-right corner with bold formatting
2. Client name and address — Place in the “Bill To” section
3. Line items — Place item descriptions and amounts in the center table area
4. Totals — Place subtotal, tax, and total fields at the bottom with larger font
5. Due date — Place near the totals or in the header area

Adjust font sizes to match your template design — amounts should stand out, while labels remain subtle.

Custom Filename Templates

Use filename templates to organize your generated invoices:

Meaningful filenames make it easy to find specific invoices later, whether you store them locally or upload to a document management system.

Combined vs. Individual Output

Choose the output mode based on how you plan to distribute invoices:

For email campaigns, use individual mode — each recipient gets their own invoice as an attachment. For internal archiving or bulk printing, combined mode is more convenient.

Sending Invoices via Email Campaigns

Combine bulk invoice generation with email delivery for a complete billing workflow:

1. Set up SMTP — Configure your email provider in Settings → SMTP
2. Design email template — Use merge fields like [[ClientName]] and [[Total]] for personalization
3. Include payment terms — Add due date and payment instructions in the email body
4. Run campaign — Each client receives their invoice as an attached PDF

Sample email template:

Subject: Invoice [[InvoiceNumber]] from Your Company

Hi [[ClientName]],

Please find your invoice [[InvoiceNumber]] attached. The amount of [[Total]] is due by [[DueDate]].

If you have any questions, please don't hesitate to reach out.

Best regards,
Your Billing Team

Best Practices for Invoice Generation

1. Use consistent invoice numbering — Ensure your spreadsheet has a unique InvoiceNumber for every row to avoid duplicates
2. Standardize date formats — Pick one format (e.g., YYYY-MM-DD) and use it consistently across all rows
3. Validate totals — Double-check that amounts, subtotals, tax, and totals are correct before merging
4. Test with 2–3 clients — Generate a small batch first to verify layout, formatting, and field placement
5. Keep a master spreadsheet — Maintain one authoritative file for all invoices, adding new rows each billing cycle
6. Archive after sending — Download generated invoices for your records after each billing run

Common Issues and Troubleshooting

Currency symbols not rendering correctly: Ensure your spreadsheet cells are formatted as text or use consistent currency formatting. If the PDF displays unexpected characters, try using plain numbers without currency symbols and add the symbol as static text on the template.

Line items overflowing the page: If you have invoices with many line items, the text may overlap with the totals section. Design your template with enough vertical space, or split long invoices into page breaks.

Client names with special characters: Names containing accents (e.g., “Cafe Rene”), ampersands, or parentheses are fully supported. Ensure your CSV file is saved with UTF-8 encoding if exporting from Excel.

Incorrect amounts after merge: Check that your spreadsheet columns contain the values you expect. Excel formulas should be calculated (copy and paste as values if needed). Leading zeros in amounts may be lost if the column format isn’t set to text.

Get Started

Upload your invoice template and client spreadsheet to the Mergram editor. Place your fields, preview with real data, and generate your entire batch of invoices in one click.