# No signal

What happens when your phone loses signal on site, and why nothing you do gets sent twice.

The engineer app needs a connection. When you lose signal you'll see **You're offline — reconnect to continue** at the top.

- What you've already saved stays saved.
- Taps that didn't go through are safe to try again. Sustainable ERP never records the same step twice, even if you tap more than once.
- Photos that didn't upload show **Failed · Retry**. Tap it when you're back in signal.

If you're somewhere with no signal for a long time (a basement plant room, say), take your photos and write your notes, then step outside to finish the job.