# One-typo matching

> Let Hide shipping methods rules match city, area and street names that a shopper mistyped by one character.

Source: https://backtrackhq.com/docs/building-rules/one-typo-matching/

Shoppers mistype addresses. "Dubae" instead of "Dubai" makes an exact match
miss, so a rule that should hide a shipping method does nothing. **Allow
one-character typos** lets a condition match values that are one character
off.

## Where it is available

The checkbox only appears in **Hide shipping methods** rules, on two
conditions:

- **City / Area**, in **Rule set one**.
- **Address line 1 and 2**, in **Rule set two**.

Every other condition and rule type matches exactly. Zip codes, phone
numbers and company names always match exactly, because one wrong digit is
a different place.

## Turn it on

1. **Open a Hide shipping methods rule and pick Rule set one or Rule set
   two.**

   (Screenshot: The Rule sets card with a set selected)

2. **Add the City / Area or Address line 1 and 2 condition, type your
   values and tick Allow one-character typos.**

   You can type several values separated by commas. See
   [Several values in one field](https://backtrackhq.com/docs/building-rules/comma-separated-values/).
   **Allow one-character typos** is off by default. Then save the rule.

   (Screenshot: The Allow one-character typos checkbox under a City / Area condition)

## What counts as one typo

One of these, anywhere in the value:

- One wrong character: "Dubae" for "Dubai".
- One extra character or one missing character.
- Two neighbour characters swapped: "Dubia" for "Dubai".

Upper and lower case never matter. With the box ticked, hyphens, dots,
commas, apostrophes and slashes count as spaces, so "Al-Gadheer" and "Al
Gadheer" are the same.

Everything that matched before still matches. The checkbox only adds near
misses.

### Short values stay exact

Values under 4 characters always match exactly. "RAK" never matches "RAS".

## Careful with negative operators

> **Caution:** With **does not contain** or **is not**, a value one
> character off now counts as a match. So the rule fires less often. The
> app shows a warning under the checkbox when you pick these operators. Use
> exact matching if a miss could give a cheaper shipping method to the wrong
> area.

> **Tip:** Put the checkbox on the rule that hides the cheap method for
> costly areas. Then the worst case is that a shopper sees paid shipping.

## In the flow editor

The flow visual editor and the rule summary add "(typos allowed)" after the
operator, for example "contains (typos allowed)". So you can see at a
glance which conditions accept typos.