Signature Request Subject Lines That Get Opened
A signature request is a transactional email with one job: get the counterparty to open the link and sign. The subject line decides whether that happens within minutes or only after a reminder. This guide sets out the patterns worth using, the ones to avoid, and how to check the result.
Start with what the evidence supports and what it does not. No single subject line wins every time; results depend on the audience, the content of the email, sender reputation, and context. What the sources behind this post agree on is narrower and more useful: clarity and relevance come first, personalization helps, and hype or padding hurts. This post publishes no completion-time data of its own, so treat what follows as a decision frame, not a benchmark.
The subject line carries real weight. One marketing source, citing Keap, reports that more than 47% of subscribers open an email based on the subject line alone, and more than 69% flag spam on the same basis. Those figures come from marketing email, not contracts, so read them as directional. A signature request differs in one way that matters: the recipient usually expects it, because a verbal agreement just happened. The subject line's job is recognition, not persuasion.
Run every draft through three checks:
- Recognition: can the recipient tell which deal this is at a glance? Name the item and, where it fits, the price.
- Action: does the line say what is being asked? The verb sign does most of the work.
- Legitimacy: does it read like a message from someone they just spoke with, not a bulk send?
Three patterns cover most trade deals. Each example below is under 45 characters.
- Item plus price. Sign for the steel diver, $4,800 (32 characters). The strongest default after a verbal deal, because it repeats the terms just agreed.
- Item plus action. Contract for your 18k ring, ready to sign (41 characters). Useful when you would rather keep the price out of the inbox preview.
- Real deadline. Hold ends Friday: sign the bracelet deal (40 characters). Use it only when hold expiry is an actual term of the deal.
Length matters because of inbox truncation. One source sets the working target at fewer than 45 characters, since longer lines risk being cut off in the inbox view. Put the words that identify the deal early, so a clipped line still says which deal it is.
Personalization helps, and for a two-party deal it is cheap. In lockd.it, the draft step takes the item, the price, and the other side's name, business, phone, and email, so the raw material for a specific subject line already exists before you send. Use the item and, if the relationship calls for it, the counterparty's name. Practitioners in a local-search forum thread on review requests reached a similar view about plain wording: the straightforward line tends to be the effective one.
Avoid these, each of which undercuts one of the three checks:
- Capitals and stacked punctuation. Sources flag lines like OPEN NOW! IMPORTANT MESSAGE! and Hi there!!!! as tactics that invite spam filtering.
- Vague lines. Quick question or Following up tells the recipient nothing about a contract waiting on them.
- Manufactured urgency. Urgency can prompt faster action in marketing email, but a false deadline on a binding document costs trust on the next deal.
- Curiosity bait. Intrigue works when it is not misleading; on a contract, mystery only makes the message look unsafe to tap.
The subject line exists only on the email channel. lockd.it lets you send the signing link by WhatsApp, SMS, email, or a copied link, and the buyer opens it on their phone with no account or app. On WhatsApp and SMS, the first line of your message does the subject line's job, so the same rules apply: name the item, state the ask, then give the link.
To find out whether a change helps, measure rather than assume. Every action on a lockd.it deal (drafted, sent, signed, finalized) is timestamped, so the interval from sent to signed is recorded for each deal. Use one pattern for a batch of deals, note the sent-to-signed intervals, then switch patterns for the next batch. Small volumes produce noisy comparisons, and deal size, buyer familiarity, and time of day all move the interval, so read the result as a signal, not proof.
The default, then: item, price, verb, under 45 characters, no capitals for emphasis, and a deadline only when one exists. Plain and specific beats clever, and a recipient who recognizes the deal in two seconds has little reason to hesitate.