Direct Mail API Pricing: Lob, PostGrid and Stannp Print and Mail Rate Cards Compared

Open lob.com/pricing and the Developer plan shows three numbers: postcard $0.905, letter $0.828, check $1.190. Nothing on that page says what class of postage those rates buy. A reasonable buyer assumes the default, and for a letter that a customer is waiting on, the default assumption is first class.

It is not. The Lob help center publishes the full grid, and the $0.828 figure is Black & White Letter, Standard Class. The first class equivalent on the same Developer plan is $1.060. That is 28 percent more than the number on the pricing page, and the difference is not cosmetic: Lob describes standard class as taking 7 to 21 business days against 5 to 7 for first class, and it is domestic only.

Here is the full letter grid, which is worth reproducing because it exists on a help page rather than a pricing page.

Now put PostGrid next to it, because the coincidence is remarkable. PostGrid publishes $1.059 for a black and white first class letter and $0.827 for black and white standard. Lob publishes $1.060 and $0.828. The two largest print and mail APIs in the United States are priced one tenth of a cent apart on both postal classes at their entry tier. On price alone there is nothing to choose between them.

The difference is disclosure. PostGrid labels every cell by class and color on its pricing page and states plainly that "Pricing Includes Printing, Processing and Postage Costs." Lob shows one unlabelled rate per plan and puts the class breakdown a click away. If you have ever budgeted a mail run off Lob's pricing page and been surprised by the invoice, this is almost certainly why.

Lob and PostGrid both advertise a $0 entry plan, and both plans stop in the same place. Lob's Developer plan says "Up to 6,000 mailings/year". PostGrid's Starter plan says "Up to 500 Monthly Mailings". Those are the same ceiling, expressed once annually and once monthly, and neither page shows you the other unit.

Five hundred pieces a month is a meaningful number. It is roughly where a transactional mail integration stops being a pilot: one letter per new account at a few thousand accounts a year, or a monthly statement run for a mid sized book of customers. In other words, both free tiers are sized to end at precisely the point where the integration starts earning its keep.

What happens next differs. Lob has a published next step, $260 a month for Startup, so you can forecast the cliff before you hit it. PostGrid does not: the page states that "If you go over 500 mailings/month on the starter tier, you will be subjected to pay an overage fee" and directs you to support for the rate. That is the single largest hole in this category's public pricing. PostGrid has the cheapest published first class letter of any vendor here, and the cost of exceeding its free tier is the one number it does not publish.

Only Mailform and LetterStream avoid the cliff entirely, because neither charges a platform fee at any volume. They pay for that with the two highest per piece rates in the comparison, $2.99 and $1.27 against PostGrid's $1.059.

Every other vendor here discounts on volume in the ordinary way: mail more, pay less per piece. Stannp does something different, and it is worth understanding before you model a large run against its rate card, because the rate card looks like the cheapest in the category.

Stannp publishes four letter tiers. Tier 1 is $1.00 up to 1,000 items, tier 2 is $0.82 from 1,000 to 9,999, tier 3 is $0.75 from 10,000 to 49,999, and tier 4 is $0.70 above 50,000. Read that alone and a 50,000 piece run costs $0.70 each. But each tier also carries a plan requirement. Tier 2 is available on Starter and above, tier 3 on Growth and above, and tier 4 is Premium only.

So a buyer mailing 50,000 letters on the $12 a month Starter plan does not pay $0.70. They pay the tier 2 rate of $0.82, because tier 4 is gated behind the $315 a month Premium plan. The volume discount is not earned by mailing volume. It is bought with a subscription, and the subscription has to be bought first.

The arithmetic still favors upgrading at that size, 50,000 pieces at $0.12 saved is $6,000 against $3,780 a year of Premium, but the structure catches people who model the rate card without reading the plan column. It also means Stannp's cheapest headline rate is unavailable to anyone spending less than $3,780 a year on the platform alone.

One more thing about Stannp that cuts the other way, in the buyer's favor: color printing is standard rather than an upcharge. Everywhere else here, color is a surcharge of 16 cents at Lob, 16 cents at PostGrid and 25 cents a page at Mailform. If your letters carry a logo or a chart, Stannp's $0.82 is competing against Lob's color first class $0.930, not against its black and white $0.890.

The cheapest way to get a direct mail API ranges from free to $2,388 a year before a single envelope is printed, and the ordering is not what you would guess from the brand names.

Mailform and Lob include API access on their $0 plans. Postalytics lists a Direct Mail API on all three plans, scoped by tier, so its free plan can drive an integration too. Stannp gates API tools behind the $12 a month Starter plan, which is the cheapest paid gate in the category and barely worth arguing about. PostGrid puts the API on Starter at $0 but caps the plan at 500 pieces a month.

Postalytics is the interesting one, because its plan ladder is close to a wash at realistic transactional volumes. Its free plan charges $1.411 for a first class simplex letter. Marketer, at $199 a month, charges $1.211. That is 20 cents saved per piece against $2,388 a year of plan, so the plan breaks even at 11,940 pieces a year, almost exactly 1,000 a month.

Below that, the free plan is cheaper despite the worse rate. Above it, the paid plan wins and keeps winning. Very few vendors in any category place a plan boundary that precisely at the median customer, and it is worth checking your own run against it rather than assuming the paid tier is an upgrade.

If you are working from a comparison article more than a year or two old, it almost certainly names Inkit alongside Lob and PostGrid. Read on 3 September 2026, inkit.com sells something else entirely.

Its product menu now lists Digital Signature, Workflows, Document Generation, File Intelligence and Records Management. There is no print product and no mail product anywhere in the navigation. Its pricing page meters signature requests: free at 3 a month, Personal at $15 per user a month billed annually or $20 monthly, Standard at $25 annually or $30 monthly, and Enterprise by quote, with "API automation" listed as an Enterprise feature.

That is a document platform with an e-signature core, not a direct mail API. We mention it because the category has consolidated quietly and the stale recommendations outlive the products. If a shortlist you were handed includes Inkit for physical mail, it was written against a product that is not on sale. What it sells now is priced on the same units as the vendors in our e-signature API pricing comparison.

The same caution applies to Click2Mail, for a different reason. Its pricing page currently answers a plain browser request with a Cloudflare block page reading "Sorry, you have been blocked". That is a block rather than a missing page, so its rate card presumably exists and is simply unreadable from here. We have left the row empty rather than fill it from a third party summary, because a price you cannot verify at source is not a price.

The comparison above answers one job. Yours will differ in ways that move the answer, so here is the order that gets to a real number fastest.

1. Fix the postage class first, before you look at any rate. This single decision moves the bill more than the choice of vendor. On Lob's Startup plan a black and white letter is $0.890 first class and $0.658 standard, a 26 percent difference for the same envelope. If the letter is a receipt, a marketing piece or a renewal notice with weeks of runway, standard class is real money. If someone is waiting on it, or a regulator is, it is not an option.

2. Count pages, not letters. Every vendor here prices the first page and then charges again per additional sheet, between $0.06 and $0.49. A two page statement is not twice a one page statement, but a six page one is close to it, and Lob adds a flat $2.495 postage surcharge above six sheets. Run the page distribution of a real month, not an average.

3. Put your monthly volume against the free tier ceilings before shortlisting. Under 500 pieces a month, Lob Developer and PostGrid Starter are both genuinely free and both cheaper than anything else here. Over 500, both cliffs bite at once and the shortlist changes completely.

4. Only then compare per piece rates, in the same class and the same color. Most published comparisons of this category compare Lob's standard class rate against someone else's first class rate and declare a winner. That is the error this page exists to correct.

If the mail you are pricing is transactional or regulated rather than promotional, the certified mail rates and the architectural fit matter more than the letter rate, and those are covered separately in best direct mail API for transactional and compliance letters. For the rendering step that has to happen before any of this, our PDF API pricing comparison normalizes twelve vendors on one job, and document generation API covers template merge.