Validate Coordinates Before API Calls

Sending bad coordinates costs a request against your hourly limit and returns a 422. A few cheap checks in your own code avoid that and give users faster, clearer messages.

The checks

1. Present and numeric. Reject null, empty strings and non-numbers.
2. In range. Latitude between -90 and 90; longitude between -180 and 180.
3. Not a placeholder. 0, 0 is often a default for "unknown". Treat it as missing unless you are sure.
4. Order. Swapped values are common. A latitude above 90 in magnitude is a giveaway that the pair is reversed.
5. Precision. Round to six decimals for storage and cache keys; see storing coordinates in a database.

A helper

function parseCoordinates(latInput, lngInput) {
  const lat = Number(latInput);
  const lng = Number(lngInput);

  if (!Number.isFinite(lat) || !Number.isFinite(lng)) return null;
  if (lat < -90 || lat > 90) return null;
  if (lng < -180 || lng > 180) return null;
  if (lat === 0 && lng === 0) return null;

  return {
    lat: Math.round(lat * 1e6) / 1e6,
    lng: Math.round(lng * 1e6) / 1e6
  };
}

Remember the field names

Resolve expects lat and lng; generate expects latitude and longitude. A helper that returns neutral names and maps them per call avoids silly mistakes.

$payload = ['latitude' => $coords['lat'], 'longitude' => $coords['lng']];

What validation cannot tell you

A coordinate can be perfectly valid and still sit in the ocean or in a country UPCS does not cover. The API answers with 422 unsupported_location for points outside the 25 supported countries; see handling the unsupported_location error.

Return friendly messages

Map each failure to something a visitor understands: "That location is not valid. Please choose a point on the map." Log the technical detail separately. The full list of responses is in the error codes reference.