Numbering invoices: auto-codes, prefixes and manual codes
Learn how Usystems assigns invoice numbers and how to customize them.
Jul 11, 2026
Every invoice needs a unique number. Usystems offers three ways to handle numbering, and you can configure which method your business uses.
| Numbering Method | How It Works | When to Use | Example |
|---|---|---|---|
| Auto-code | System generates a sequential number each time you confirm an invoice. The format is typically a prefix (optional) followed by an incrementing number. | Most common; simplest for most businesses. | INV-00001, INV-00002, or 001, 002 |
| Prefix + auto | You set a text prefix (often your business initials or location code), and the system appends a running counter. | Useful if you have multiple locations or product lines and want invoices grouped by prefix. | NYC-INV-001, LA-INV-002, or RETAIL-001, BULK-002 |
| Manual code | You type the invoice number yourself when creating the invoice. | Rare; used only if you must match a pre-existing numbering scheme or have a special requirement. | APR-2026-042, CUSTOM-789 |
Configuration (admin only) Invoice numbering is set in Settings → Business Settings or Settings → Products (if per-product). Admins can choose the numbering method, set the prefix, and reset the counter if needed.
Behavior & notes
- Once you confirm an invoice, the system locks its number. You cannot change it.
- If you discard a draft before confirming it, no number is assigned.
- If you use auto-code, the system remembers the last number used and increments. If you delete or void an invoice, the counter does not reset (so you may see gaps in the sequence—this is normal and safe).
- Manual codes are useful for special cases but are your responsibility; the system does not check for duplicates if you enter the same number twice.
- Leading zeros (001, 002) are preserved in auto-codes, making numbers easier to read and sort.
Cross-product numbering If your business has multiple ref_products (e.g., pharmacy and accounting divisions), each can have its own numbering scheme. Configure each separately in settings.
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