Black Friday inventory and delivery: no more overpromising

Key takeaways

Sellable balance = physical inventory − reserved − paid and not yet shipped; it is the only number a salesperson may use.
Late or missing delivery was the top complaint on Black Friday 2025: 32.19% at Procon-SP and 23.25% on Reclame Aqui.
Delivery time is counted from confirmed payment, never from the conversation, and includes picking time plus the carrier's time.
A reservation with no expiry is blocked inventory; set a deadline (for example, 2 hours) and what happens when it runs out.
Under the Brazilian Consumer Protection Code (CDC, art. 35), if the offer is not honored, the customer can demand the product, accept an equivalent or walk away with a full refund.

Why are inventory and delivery time the biggest Black Friday risk?

Because that is where most complaints are born, and because the promise is made by someone who does not control delivery. According to Procon-SP, the São Paulo consumer protection agency (2025), 32.19% of the 1,873 Black Friday complaints were for late or missing delivery. On Reclame Aqui (2025), 23.25% of the more than 8,600 complaints were about delays and 12.68% about products not received.

On WhatsApp the risk is higher than on a website, because the promise is made by a person, in real time, with the information they have at that moment. If the agent sees "5 units" in the morning spreadsheet and sells 5 in the afternoon, not knowing that 3 were reserved by a colleague, two customers get apologies instead of the product. And volume is growing: according to Confi Neotrust (2025), there were 21.5 million orders, 16.5% more than in 2024, with a lower average order value.

What is the sellable balance and how do you keep the number right?

The sellable balance is the quantity that can still be promised to a new customer: physical inventory minus what is reserved and minus what is paid but has not left yet. Only that number may appear in a conversation.

Product status	Counts in the sellable balance?	Who updates	When
Physical, on the shelf	Yes	Inventory	Count at the start of the day
Reserved (customer asked for the link, has not paid)	No, until the reservation expires	Agent, when sending the link	Immediately
Paid, not shipped	No	Finance, when confirming payment	Immediately
Shipped	No (already gone)	Dispatch	Immediately
Returned and inspected	Yes, after inspection	Inventory	When it is back on the shelf

Operating rules:

One official source. Spreadsheet, inventory system or CRM: choose one and ban the others. Two sources produce two balances.
One owner, fixed times. In a manual operation, update the balance at least every 2 hours during Black Week and show the time of the last update where the agent can see it.
Pending data is stated as pending. "Let me confirm we still have it and I'll get back to you in 10 minutes" beats a promise based on a stale balance.
Funnel stages mirror inventory. A CRM with a visual funnel, such as RASTRO, allows "proposal sent" (reserved) and "paid" (deducted from the balance) stages; counting the cards in each stage shows how many units are committed.

How does product reservation work on WhatsApp?

A reservation is a temporary hold on the balance in the name of a customer who asked for the link and has not paid yet. It needs an expiry, because a reservation without a deadline is idle inventory.

A template to adapt:

Expiry: 2 hours for Pix and card links; until the end of the day for boleto (bank slip), if you accept boleto on Black Friday.
What guarantees the product: confirmed payment, not the reservation. Say so in the link message: "I've reserved one unit for 2 hours; the order is guaranteed once payment is confirmed."
When it expires: the agent sends one reminder and the unit goes back to the sellable balance.
Who extends it: only the manager, and only if there is balance.

Decision rule: if a product has fewer than 10 units of sellable balance, cut the reservation expiry to 30 minutes and pause that product's ad. The link stage is covered in from link sent to payment confirmed.

How to calculate the delivery time you can promise?

Add picking time to the carrier's November transit time and count everything from confirmed payment. October's transit time does not hold in November.

Promised delivery time = picking and posting + carrier transit time + safety margin

Hypothetical example for a store with 2 people in dispatch:

Picking capacity: each person picks and packs 25 orders per day → 50 orders/day.
Order projection: 90 per day during Black Week. At 50 per day, the backlog grows by 40 each day; by Friday there are 160 in the queue, that is, 3.2 business days until Friday's order is posted.
Carrier transit time: checked for November, 4 business days in the main region (October's quote said 3).
Safety margin: 1 business day.
Delivery time to promise on Friday: 3.2 + 4 + 1 ≈ 8 business days after payment (round up, never down).
Decision: promise 8 business days, or hire temporary help in dispatch (100 orders/day, backlog cleared) and promise 5. The extra help costs one day laborer for 6 days; the backlog costs complaints and cancellations.

Always write "X business days after payment confirmation"; "arrives in 5 days" is read as 5 calendar days from the conversation. How capacity limits the target is in a 30-day plan to sell on WhatsApp.

What to do when inventory runs out mid-campaign?

Offer an alternative approved before the campaign, in the same message where you announce the stockout. For every product on offer, decide beforehand:

Situation	Approved alternative	What the agent says
Sold out, restock within 5 days	Waitlist with a stated date	"It sold out today; a new batch arrives by [date]. Want to join the list with the Black Friday price guaranteed?"
Sold out, no restock	Equivalent product under the same conditions	"It sold out. Model [B] does the same job and goes for the same price. Want to see it?"
Sold out after payment	Equivalent or full refund, at the customer's choice	"There was an inventory error. You choose: model [B] at no cost, or a full refund right now."

The "sold out after payment" case is the most delicate, and the law is clear: under art. 35 of the Brazilian Consumer Protection Code, when the supplier refuses to honor the offer, the consumer can demand specific performance, accept an equivalent product or walk away with a full refund plus damages. The choice belongs to the customer, not the store; "credit toward your next purchase" as the only option is not allowed.

Which common mistakes lead to wrong promises?

The four most common mistakes:

Selling from physical inventory. "We have 5" when 3 are reserved. Use the sellable balance.
Morning data holding all day. On Black Friday, 5 units vanish in an hour. Agree on update times and show the time of the last data point.
Delivery time counted from the conversation. The customer pays on Monday, the store promised "5 days" on Friday, and the order arrives "late" without being late.
October transit time in November. Check with the carrier for the period and, if the transit time goes up, update the offer immediately. Where delivery time goes in the message is in how to build a clear offer.

What to measure to know whether promises are being kept?

Measure cancellations due to stockouts and orders delivered late, separating information failures from carrier delays, because the fix is different.

Metric	Formula	Good	Bad
Cancellation due to stockout	orders canceled for lack of inventory ÷ paid orders	zero	anything above 1% (the sellable balance is wrong)
Orders delivered late	orders delivered after the promised time ÷ orders delivered	below 5%	above 15%
On-time internal posting	orders posted within the picking time ÷ paid orders	above 95%	below 80% (internal bottleneck)
Expired reservations	reservations expired without payment ÷ reservations created	below 40%	above 60% (expiry too long or offer unclear)

If internal posting is good and delivery is bad, the problem is the carrier: switch or increase the margin. If both are bad, the problem is dispatch: reinforce or reduce traffic. Where to track these numbers is in dashboard: what the business owner should look at.

Frequently asked questions

Sources

Can I sell before confirming inventory?

You can record interest, making that explicit ("let me confirm and I'll get back to you"). Do not confirm availability or delivery time without an updated sellable balance. Under art. 30 of the CDC, the salesperson's confirmation on WhatsApp binds the business; "yes, we have it" is an offer, not a conversation.

What to do if the carrier is late?

Tell the customer before they ask, with the new delivery time and the tracking code. A communicated delay is an inconvenience; a delay the customer discovers is a complaint. If it goes beyond what is reasonable, offer the options under art. 35 of the CDC: wait, an equivalent or a full refund.

Can I sell with delivery only after Christmas?

Yes, if the delivery time is written in the offer and accepted by the customer before payment. "Delivery from Dec 28" in the message is a clear condition. The mistake is selling in November with a vague delivery time and discovering in December that it will not arrive before the 25th.

How do I control inventory for a service or a schedule, like a clinic or a salon?

The sellable balance of a service is the number of open slots. The reservation is the slot blocked without payment, with the same expiry logic: 2 hours to confirm, then the slot becomes available again. Overbooking the schedule is the service version of late delivery.