Ordinary signature service answers an evidence question. The adult version answers a compliance one, and it costs about twice as much.
A real 8 lb box, and the adult signature on top of it
The anchor is a 14 x 12 x 8 in box at 8 lb, quoted 2026-07-28 from Newark, NJ 07102 to Atlanta, GA 30303. USPS Ground Advantage came back at $15.73 and FedEx Ground Economy at $15.64, each the full amount at checkout. Adding an adult signature roughly doubles what that shipment costs.
SMKlog rates for the anchor box, quoted 2026-07-28
| Carrier | Service | Price | Quoted transit |
|---|---|---|---|
| FedEx | Ground Economy | $15.64 | 6-7 business days |
| UPS | Ground Saver | $15.71 | no window supplied on this rate |
| USPS | Ground Advantage | $15.73 | 8-9 business days |
| UPS | Ground | $20.02 | 2-3 business days |
| UPS | 3 Day Select | $22.23 | 5-6 business days |
Adult signature across the three carriers
USPS fee from Notice 123 on pe.usps.com, effective 2026-07-12 and re-checked 2026-07-28, with the age rule from usps.com/ship/insurance-extra-services.htm. UPS fee from the revised value-added services rates effective 2025-12-22 and the rule from the UPS Tariff/Terms and Conditions of Service, United States, section 34.2. FedEx fee and rule from the FedEx Service Guide 2026. All fetched 2026-07-28.
| Carrier | Fee | Who may sign | Rate plus fee on the anchor box |
|---|---|---|---|
| UPS | $9.35 | An adult 21 years of age or older; UPS may ask for photo identification showing age | $29.37 with UPS Ground at $20.02 |
| USPS | $9.70 | An adult aged 21 or over | $25.43 with Ground Advantage at $15.73 |
| FedEx | $10.00 | Someone at least the age of majority in the destination country, with government photo identification required | $25.64 with Ground Economy at $15.64 |
The right-hand column pairs our quoted rate with the carrier's published fee; add-ons are actually priced in checkout against the service you choose, so read it as the two published figures side by side. Even so, the shape holds: on a box this size the signature costs about as much as the postage.
A Shipper may request UPS to obtain the signature of an adult 21 years of age or older on Delivery.UPS Tariff/Terms and Conditions of Service, United States, section 34.2, ups.com, fetched 2026-07-28
When nobody qualifies at the door
None of the three simply leave the box. FedEx states that if there is no eligible recipient at the delivery address it may reattempt delivery. UPS decides at its own discretion whether the delivery can be completed. USPS follows its ordinary attempted-delivery path, which means a notice and a trip to the Post Office for the recipient. Every one of those outcomes adds days, so an adult signature on a time-sensitive shipment is a trade, not a free upgrade.
The shipments where it is not optional
| Goods | Requirement | Source |
|---|---|---|
| Alcoholic beverages moving with UPS | Contract service, licensed shippers only, adult signature on every package plus a special UPS alcoholic beverages label | UPS tariff section 3.4 |
| Hemp products moving with UPS | Adult signature requested at the time of delivery on every shipment | UPS tariff section 3.5 |
| Firearms and firearm products with UPS | Adult signature and Direct Delivery Only, with outer markings that do not identify the contents | UPS tariff section 3.7.1 |
| Hazardous materials with FedEx, other than limited quantity | Shipper must select Direct Signature Required or Adult Signature Required; signature release and driver release are unavailable | FedEx Service Guide 2026 |
Most of that list is academic here. Alcohol, firearms, ammunition, marijuana, hemp and kratom are all on our restricted and prohibited lists and cannot be bought a label through SMKlog checkout, whichever signature you were prepared to pay for. The table matters because it tells you why a carrier would refuse a shipment you thought was ordinary.
Twenty-one is not a delivery-industry standard
USPS and UPS both name 21. FedEx names the age of majority in the destination country, which inside the United States generally means 18. If the rule you are meeting is a state alcohol law, that difference is the whole point.
Commercial addresses behave differently
An office reception can absorb an ordinary signature all day. An adult signature with an identification check is harder to complete at a busy front desk, and a failed attempt costs a day. Send to a home where someone will be in, or expect a redelivery.
Ordinary confirmation is usually enough
If the goal is evidence for a dispute rather than compliance with a rule, the cheaper signature product does the same job. USPS lists Signature Confirmation at $4.15 electronic against $9.70 for the adult version.
Adult signature questions
How much does adult signature cost?
$9.35 at UPS, $9.70 at USPS and $10 per package at FedEx, from the carriers own published 2026 rate documents fetched on 2026-07-28. Each is charged on top of the postage.
What age counts as an adult for delivery?
USPS and UPS both require someone 21 years of age or older. FedEx requires someone at least the age of majority in the destination country and states that government-issued photo identification is required.
What happens if no adult is home?
The package is not left. FedEx may reattempt delivery, UPS decides at its own discretion whether delivery can be completed, and USPS leaves a notice for collection. Each outcome costs at least a day.
Which shipments require an adult signature?
UPS mandates it for alcoholic beverages, hemp products and firearms, and FedEx requires a direct or adult signature on hazardous materials other than limited quantity. Those goods sit on the SMKlog restricted list and cannot be bought a label here.