> ## Documentation Index
> Fetch the complete documentation index at: https://docs.byblend.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Why doesn't my order quantity match the prescribed quantity?
> They measure different things. A prescription quantity is in the prescriber's units — 20 mL. An order line quantity counts sellable units — 2 vials. Set quantity explicitly on every order line.
Blend tracks quantity at three different layers, and they are not interchangeable.
* **Prescription quantity** — what the prescriber wrote, in clinical units. *20 mL.*
* **Order line quantity** — how many sellable units to dispense. *2 vials.*
* **Dispensed quantity** — what was actually pulled at pick time, recorded on the fill.
## When you create the order
Blend does **not** compute the line quantity for you. If you omit `quantity` on an order line, it defaults to **1** — regardless of what the prescription says. A 90-capsule prescription with no `quantity` on the order line ships one bottle.
Send it explicitly:
```json theme={null}
{
"patient": { "external_id": "clinic-pt-4471" },
"products": {
"prescription": [
{ "product_code": "HC-RAPA31", "quantity": 2 }
]
}
}
```
## How many fills does that consume?
At pick time, Blend works out how many refills the dispensed amount represents:
| Prescription | Ordered | Fills consumed |
| -------------------------- | ----------- | -------------- |
| 90 capsules, 90 per bottle | 1 bottle | 1 |
| 30 capsules, 90 per bottle | 90 capsules | 3 |
| 20 mL, 10 mL vials | 2 vials | 1 |
`fills_remaining` on the prescription is the number to trust — it accounts for how much each fill actually consumed, and it excludes fills created by [replacement orders](/guides/replacement-orders), which deliberately don't count against the prescription.
Set `quantity` on every line
Correct a line in `received`
`quantity`, `units`, `fills_remaining`
NCPDP unit codes