Lob Help Center

Mailing class, postage, & distribution

What are mailing classes? 

As Lob leverages USPS as our mail delivery carrier, the USPS offers a number of mailing services to suit the needs of the business. Leverage different mailing class options based on your time sensitivity, budget, and need for other adjacent services.

First Class Mail

  • Used to send Lob postcards, self-mailers, letters, and checks
    • Intended mostly for personal or business correspondence
    • Invoices, statements, and other confidential mail that include PII/PHI or sensitive data of any kind must be sent via First Class or risk being flagged by USPS and taken out of the mail stream
    • Businesses have the option of adding on additional services, like Certified Mail
  • Must weigh 13oz or less; anything over 13oz can be sent as Priority Mail
  • First Class delivery is given priority over Standard Mail, both locally & nationally
  • Includes forwarding and return services with no additional charge 
  • Domestic mailings typically take 4-6 business days, and international mailings typically take an additional 5-7 business days to be delivered

Standard Class Mail or Marketing Mail

  • Broadly known as Marketing Mail, or "bulk mail" in the industry
    • Lob will often refer to it by its previous name, Standard Class Mail, in our product offerings 
  • Used to send Lob postcards, self-mailers, and letters with marketing-related content
    • Intended more for advertisements and mass communication purposes 
    • Must not contain any sort of sensitive personal information or PII outside the address box
  • Must weigh 16oz or less, and meet a minimum quantity of 200 pieces or 50lbs of mail
  • Processed by USPS on a "time available" basis; no delivery time guarantees provided by USPS
    • Best to avoid with time-sensitive mailings 
  • Least expensive postage mode available on Lob
  • Mailings typically take 7-21 business days (only available in US; no international service)
  • Standard mail is not forwarded or returned if undeliverable unless a special endorsement is used; undeliverable mail will be destroyed by USPS 

Note: Any mailpiece that contains PII or PHI must be sent as First Class and cannot be sent as Standard Mail per USPS regulations. Non-compliance will result in potential removal of your mail batch from the mailstream, customer delays, and/or order cancellation. 

Nonprofit Marketing Mail

  • Saves authorized nonprofit organizations up to 70% of the cost of First Class mail 
  • Only available for domestic mail
  • Follows the same delivery times as Standard mail

Lob currently does not offer any overnight/express mailing options. 

Delivery times are estimates and will vary depending on product and destination. As our primary mail carrier, the USPS also experiences delays from time to time. To see the most up-to-date status of your mailing, check the tracking information of your particular mailing through a GET request or on your Dashboard. 

You can also view the latest information on USPS delivery times on the USPS interactive map

USPS Marketing Mail eligibility

As marketers are adding greater amounts of "personal information" in their direct mailings that include advertising mailers typically sent as USPS Standard Class or Marketing Mail, USPS has added greater scrutiny around which class of mail can be utilized given the level of "personal information" included in your mailers.


These Marketing Mail eligibility standards have been in effect since June 1, 2005, and are enforced at the discretion of the USPS Customer Support Rulings agent. The main conclusion: Standard Class (aka Marketing Mail) should not be utilized for sending mail that includes personal information or sensitive data in any way. If you are planning any Marketing Mail campaigns that include the personal information of the recipient, make sure to mail it First Class to avoid USPS rejection which will result in delays for your mail.

Lob cannot currently prevent customers from sending personal information or sensitive data as Standard Class Mail. Consult your Customer Support Manager for further guidance on eligibility.

Available mailing class options


  • 4x6, 6x9 and 6x11 postcards: Mailed via USPS First Class Mail (takes 4-6 business days and international mailings take an additional 5-7 business days). 
  • 6x9 and 6x11 postcards: Mailed via USPS Standard Class Mail (takes 7-21 business days) and only within the US.


  • Mailed via USPS First Class Mail or Standard Class Mail
  • USPS Standard Class Mail may only be used for sends within the US


  • Mailed via USPS First Class Mail (takes 4-6 business days)
  • Mailed via USPS Standard Class Mail (takes 7-21 business days) and only within the US


  • Mailed via USPS First Class only (takes 4-6 business days)
    • USPS Standard Class Mail is not available for checks 
  • Overnight/expedited mailing options are not available 


Our fulfillment partners programmatically print their own indicia on all postcards and self-mailers. This indicia is then used to prepare the mailing paperwork for USPS.

Our return envelopes are blank and come without prepaid postage; mail recipients will be responsible for adding their own postage when sending reply mail.

Mail collection & cut-off times

Our daily cut-off times for all mail submissions are 10am PST each business day; anything submitted after that will be processed in the following business day's production run.

Remember: if you use the cancellation window or scheduling feature and your send date surpass a daily cut-off time, it will be slotted for the next production day. Production days are based on normal business days, including National Holidays.

If you have more questions regarding cut-off times, reach out to support@lob.com or your Customer Success Manager.

Mail distribution to Lob's PDN

Lob's Print Delivery Network (PDN) is the backbone of our Print & Mail offering. By replacing traditional print vendor relationships with an integrated, on-demand network of distributed commercial printers, we simplify client print operations and vendor management experience. Qualified commercial printers are thoroughly vetted by our team and integrated into our larger ecosystem of print partners, enabling our customers to access automated production, increase daily throughput, and optimize for consistency and quality on-demand and at scale.

Any mail that is sent through Lob is dynamically distributed to eligible print partners within our PDN based on a number of factors, including:

  • Mail form factor and permutation availability
  • Mail volume capacity
  • Paper stock and ink availability 
  • Distance from end-recipient of mail
  • Other manufacturing and logistical capacity needs
  • Regulatory requirements (e.g. HIPAA)

There are three methods for customers to send mail: Immediate, Scheduled, and Targeted.  

Immediate (or "ASAP") mailings 

Generally speaking, Lob mail will be immediately sent and routed to production upon customer submission of mail orders, pending any cancellation rules applied at the account or campaign level. This is the default API setting for Lob mailings that is available to all customers.

See Mail data & tracking on how to track individual mail pieces at each step of the production and delivery process, and see webhooks on setting up and surfacing tracking notifications.

Scheduled mailings

Mail sends can be scheduled up to 180 days in the future. Until that time, mailings can also be canceled. You can use this feature to:

  • Create automated drip campaigns (e.g. send a postcard at 15, 30, and 60 days)
  • Schedule recurring sends
  • Plan your mailing schedule ahead of time

See Mail Send Settings for more details on how to schedule mailings for a future date. If you use this feature in conjunction with a cancellation window, the send_date parameter will always take precedence.

NOTE: This feature is only available to Enterprise edition customers. Contact Sales or your CSM to gain access to this feature.

Targeted delivery date mailings

Coming soon.

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