Picture the person you are about to send a contract to. They are not at a desk. They are holding a phone, possibly an older Android, on mobile data, in a building where the signal drops when they walk to the back office. They have never used your signing tool and they were not expecting your email.
That person is the actual user of an electronic signature product. Everything else — the sender’s dashboard, the templates, the integrations — is arranged around getting them to a successful signature. If the tool works beautifully on a laptop and badly on that phone, the tool does not work.
What the signer should have to do
The whole interaction, at its best, is short.
They open a link. The document loads, and they can read the real pages, not a summary or a thumbnail. They scroll. They tap a field, draw or type their signature, tap confirm. If a code was required, they receive it by SMS and type it in. A confirmation appears. The signed file arrives by email.
Note what is not in that list. No account to create. No password to remember, or to reset three minutes later. No application to download, which matters a great deal on a phone with two gigabytes of storage and no room for another app. No desktop step hidden in the middle.
If any of those creep in, adoption dies quietly. The signer does not complain; they just phone the sender and ask them to send it the old way.
What breaks on a weak connection
Three things, and they are worth knowing by name so you can test for them.
The document never appears. A signing page that fetches the whole PDF at full resolution before rendering anything will sit on a blank screen for a long time on mobile data. A well-built one shows the first page quickly and loads the rest as the signer scrolls.
The signature is lost on submit. The signer fills everything in, taps confirm, the connection drops, and the page comes back empty. This is the single most damaging failure, because the signer now believes the tool ate their work and will not try again.
The SMS code arrives late, or after the page has given up. Delivery times vary by network and time of day. A page that expires the code in sixty seconds will fail for real people on real networks.
How to test before you commit
This is the part most buyers skip, and it is the cheapest insurance available.
Before you sign a contract with any provider, send yourself a real document. Not a demo on their laptop in a meeting. A real one, to a real phone, on mobile data, at a normal time of day in a normal building.
Then send one to the least technical person you work with and watch them do it without helping. Watch where they hesitate. That hesitation is what will happen a hundred times a month once you roll it out.
Then, if you can, do it once on a genuinely poor connection. Walk into the stairwell.
Three tests, half an hour, and you will know more about the product than any feature list will tell you.
What the sender can do to help
Send at a sensible hour. A document that arrives at eleven at night gets opened the next day at best.
Name the document properly. “Service agreement — Diallo & Fils — April 2026” in the subject line tells the signer this is legitimate before they open anything. Generic subject lines look like fraud, and people are right to be careful.
Warn them it is coming. One message, in whatever channel you already use with that person: I am sending you the contract to sign, it comes by email, it takes two minutes on your phone. This single sentence removes most of the hesitation.
Keep the document short where you can. A forty-page PDF is a lot to scroll on a handset. If half of it is annexes, consider whether they all need to be inside the signed file.
Do not require anything you do not need. Every optional field a signer has to think about is a place they stop.
Where this comes from
We build for signers on phones because that is who signs here, not because mobile is a feature to advertise. The design rule we hold ourselves to is that the signer never had a choice about being in this flow: they received a link from someone else, on a device we did not pick, on a network we do not control. Their path has to work the first time.
Judge any provider on that, and test it yourself rather than taking anyone’s word for it. Ours included.
The e-signature product page walks through the signer’s path, and pricing covers what SMS challenges cost, in Guinean francs.