The differences are practical rather than legal — both are checks — but they determine which stock to buy and how to configure the software.
Side by side
| Personal | Business | |
|---|---|---|
| Typical size | About 6 x 2.75 in | About 8.5 x 3.5 in |
| Per letter sheet | Three, no stubs | One check plus one or two stubs |
| Check number in MICR | Inside the on-us field | Often in the auxiliary field at the left |
| Stub | None | Payment detail for the payee and your records |
| Signature lines | One | One or two, depending on account rules |
| Address block | Personal name and address | Company name, address, sometimes a logo |
What the stub is for
The stub is the reason businesses use voucher checks. It carries the detail the payee needs to apply the payment:
- Invoice numbers and dates
- Amount applied to each invoice
- Discounts taken
- Purchase order references
- A running total
A vendor receiving a check with no remittance detail has to phone and ask what it pays, which is where the administrative cost of the whole process actually sits. With two stubs, one goes to the payee and one stays in your file.
The auxiliary field
On business checks the check number is commonly printed in an auxiliary field at the far left of the MICR line, before the routing number, rather than inside the on-us field. Your check printing software needs to know which convention your bank uses. Copy the arrangement from an existing bank-issued check for that account rather than guessing.
Two signature lines
Some businesses require two signatures above a threshold. The second line is a control rather than a bank-enforced rule in most cases — banks generally do not verify the number of signatures on a check during automated processing, so treat it as an internal policy that also needs internal enforcement.
Which to print
- Household payments, contractors, one-off payments to individuals: personal format, three per page, cheapest per check.
- Anything with an invoice behind it: voucher format with a stub.
- Payroll: voucher format, usually check-in-the-middle, so the stub can carry the earnings detail. See printing payroll checks.
Using both from one program
There is no reason to be limited to one. A household with a side business commonly runs both formats on separate accounts, and reasonable check printing software keeps accounts, formats and number sequences separate. Just keep the paper stacks physically apart, and give each account its own non-overlapping number range.