Purchase limits

Medical marijuana purchase limits: how to track them at the counter

Oklahoma sets purchase limits for patients by product type. This guide is about the operating side: how limits are counted, where the numbers come from, and how a point of sale should enforce them.

Last reviewed October 2026 · For licensed Oklahoma dispensary owners and managers

How a limit is counted

A purchase limit is a cap on how much of a product type a patient takes home. To check it, every item in the cart has to answer two questions:

1. Which limit does it count toward? This comes from the product's category, or from the package's category in Metrc.
2. How much does it count? For items sold by weight, the quantity sold. For items sold by the each, the quantity times the weight of one unit, using either unit weight or net weight depending on the product type.

Get either answer wrong and the limit check is wrong, even if the cap itself is set correctly. That is why most purchase-limit problems are really product-setup problems.

This guide does not state the legal amounts. They are set by OMMA and can change; take them from the current rules and enter them yourself.

Whose category and weight?

Your product catalog and Metrc can disagree. A supplier may list a package in Metrc under a different category than you filed the product, or with a different unit weight. When they disagree, you need a rule:

• Use Metrc's package data. Metrc is what an inspector reads, so counting the way Metrc does means the counter and the state agree. The risk: supplier data entry errors in Metrc count against your patient.
• Use your own product setup. You control the data. The risk: a sale can look within the limit to you and over it by Metrc's numbers.
• Use whichever is stricter. Count the heavier weight, and when the categories name different limits, count toward both. This never allows more than either of the other two would.

Whatever you choose, fix disagreements at the source. Change the product when your setup is wrong; ask the supplier to correct the package when Metrc is wrong.

Setting limits up

• Enter each limit from the current OMMA rules, with the right unit (grams, ounces, milligrams or each) and the right weight basis.
• Give every regulated category a purchase-limit type. A regulated product in a category with no limit type cannot be counted.
• Give every product sold by the each a weight. Check items where the weight field holds a dose rather than a weight.
• Map your categories to Metrc categories, so packages are placed under the right limit.
• Run a test cart at or just over each limit before opening.

At the counter

• Show the running total. Staff should see how close the cart is to each limit as they ring it up, not only when checkout fails.
• Remove items, do not argue with the check. When the cart is over, take items off. If the check looks wrong, set the item aside and have a manager fix the product setup afterwards.
• Watch for split purchases. Several back-to-back sales to the same patient that together go over a limit is a pattern inspectors notice. Know your store's policy.
• Offline is not a loophole. A register working offline should apply the same limits and refuse items it cannot count.

Weekly review

1. List sales that went over a limit, by your numbers and by Metrc's.
2. List products whose category or weight disagrees with Metrc, starting with the ones that count less than Metrc.
3. List products with no category or no weight that are in stock.
4. Fix the products, and contact suppliers about packages where Metrc is wrong.

How GreenPOS does it

• Per-transaction, hard stop: limits are checked on the cart at checkout. Over a limit, checkout is blocked with a message naming the limit and the amounts, and there is no override.
• Settings → Limits holds the cap, unit and weight basis for each limit type. Oklahoma stores cannot save a limit that is blank, zero or above the legal amount.
• Count purchase limits using offers Whichever is stricter (the default for new stores), Metrc's package data or My product setup. Only admins can change it, every change is logged, and past sales are judged by the choice in force when they were rung up.
• Today's purchases: once a customer is selected, a Today: line shows what they have already bought today toward each limit, for reference.
• Missing data blocks the sale: a limit-counted item with no weight, or a Metrc-tracked item that no category can place under a limit, is refused with a message naming what to fix.
• Review lists: Compliance → Purchase Limits shows sales over the limit by Metrc's numbers in the last 30 days and products set up differently from Metrc, with Match Metrc to correct a product. Products → Metrc mismatch shows the same products.
• Offline: the offline register runs the same rule from its saved copy and refuses items that are not in that copy.
• Morning email: admins can turn on Email me about products that don't match Metrc for a 7 AM list of new mismatches and new over-limit sales.