Biller Genie's default invoice email templates are tuned for deliverability — short, transactional subject lines and clean message bodies that look like the legitimate transactional email they are, not a marketing blast. When you customize the templates, the choices you make affect whether your customer's email provider routes the message to the inbox or to the junk folder. This article covers the email templates Biller Genie sends, what good and bad customization looks like, and how to confirm your changes still deliver.
!!!, words like "LIMITED TIME OFFER" — trigger spam filters at Google Workspace, Microsoft 365, and most corporate email gateways. The default templates avoid all of these patterns on purpose. The bigger the change you make, the higher the chance your email lands in spam.Where the templates live
Editable email templates are inside the two Add-Ons that send email on your behalf:
- Add-Ons > Invoice Messenger — the "New Invoice," "Paid Invoice," and manually-sent "Invoice" templates.
- Add-Ons > Reminders — the "Invoice Reminders" sent on schedules.
Each template has editable Subject Line and Message Body fields, plus a Header that comes from your Branding setup.
Templates by invoice lifecycle stage
| Template | When it sends |
|---|---|
| New Invoice | Automatically sent when a new invoice is created and synced from your accounting software. |
| Invoice (manual send) | Sent on demand when you click "Email" on an invoice. Same template editable separately so you can craft a more personal voice for one-offs. |
| Invoice Reminders | Automatically sent based on the reminder schedule and rules configured under Add-Ons > Reminders (days before/after due date, cadence, escalation tone). |
| Paid Invoice | Automatically sent once an invoice is marked as paid — confirms to the customer that you received their payment. |
Subject line best practices
Do this
- Keep subject lines short — 40–60 characters is the sweet spot. Anything longer gets truncated on mobile.
- Include the invoice number so the customer can match the email to a specific invoice.
- Reference your business name using the
{DBAName}merge tag so customers recognize the sender on sight. - Use neutral, transactional language — "Invoice," "Payment Receipt," "Statement," "Reminder."
Solid examples:
Invoice #{InvoiceNumber} from {DBAName}New Invoice: #{InvoiceNumber}Paid: Invoice #{InvoiceNumber}Reminder: Invoice #{InvoiceNumber} from {DBAName}
Avoid this
-
Excessive punctuation —
!!!,???,$$$. - ALL CAPS on words other than your acronym brand name.
- Emojis — even friendly ones. Transactional emails don't use them.
- Urgency/sales language — "ACT NOW," "FINAL NOTICE," "LIMITED TIME," "MUST OPEN."
Bad examples (will hurt deliverability):
PAY NOW!!!FINAL NOTICE – ACT FASTYou must open this email immediately
Message body best practices
Email providers also analyze the body text. The same rules apply: look transactional, not promotional.
- Keep the message professional and invoice-focused. Lead with what the email is about ("This is your invoice for...") rather than warming up with marketing language.
- Use standard punctuation and capitalization. Avoid large blocks of bold or colored text.
- Avoid extra links. The Pay Now button is the call to action — adding more links (social media, marketing) reduces the focus and looks like a marketing email to spam filters.
- Limit repeated urgency keywords (e.g., "overdue overdue overdue"). One mention is fine; piling them up gets flagged.
- If you want to upsell or share news, send a separate marketing email through a marketing tool — not on top of your invoice template.
Useful merge tags
Biller Genie supports merge tags inside subject lines and message bodies. The most-used:
| Tag | What it inserts |
|---|---|
{InvoiceNumber} |
The invoice's reference number (e.g., 1024) |
{DBAName} |
Your business name (as displayed in Biller Genie) |
{CustomerName} |
The customer's display name |
{InvoiceTotal} |
The invoice amount (formatted as currency) |
{DueDate} |
Invoice due date |
{PaymentLink} |
The unique payment link for this invoice |
Click the Merge Tag picker inside the Invoice Messenger or Reminders editor to see the full list of merge tags available in your account.
Why the defaults are recommended
Biller Genie's default templates are tuned over years of real-world delivery data — they're shaped to:
- Align with transactional email best practices.
- Pass common spam-filter and sender-reputation checks.
- Deliver consistently across Google Workspace, Microsoft 365, and most corporate gateways.
- Be recognized by major B2B mail filters as legitimate billing email.
Customize lightly — change your business's tone of voice, add a thank-you line, swap "Invoice" for "Statement" if your industry calls it that — but keep the underlying structure intact.
Testing changes before they go live
- Send a test invoice to yourself at a personal email address (Gmail, Outlook, Yahoo — any inbox you don't control). This mirrors what a real customer sees.
- Confirm the email landed in the inbox, not Spam or Promotions.
- Open the email — check that merge tags rendered correctly (no leftover
{InvoiceNumber}text). - Click the Pay Now button — confirm the link resolves to the hosted payment page.
- Wait 24 hours, then check a customer reminder that should have sent in that window — confirm it still delivers and looks right.
If a customized template starts landing in spam, revert to the previous wording. You can keep the original subject/body in a note (or run View History if your template supports it) so you can roll back.