Nextail is an AI platform for managing stock allocation, replenishment and rebalancing, with plans for brands with 10 or more stores.
If your business is smaller, Datcisions is an alternative: an AI merchandise planning tool for fashion brands that calculates, size by size, what to buy and what to send to each point of sale.
What is Nextail?
A company founded in Madrid in 2014 that helps fashion chains allocate and move stock between stores and channels. Its software connects to enterprise resource planning (ERP), warehouse and point-of-sale systems.
Its plans are designed for brands with 10 or more stores. The client references it publishes include River Island, Gina Tricot and Hackett London.
What does a brand with a few stores need?
Irene heads purchasing at a knitwear brand with four stores and an online store on Shopify. (This is an illustrative case, with made-up figures excluding VAT.)
For autumn, she buys 400 jumpers of her best-selling style, at a cost of €25 and a selling price of €60: €10,000 invested in a single product. She orders 120 S, 160 M and 120 L, just like the previous season.
| Size | Purchased | Sold at full price | Left over |
|---|---|---|---|
| S | 120 | 70 | 50 |
| M | 160 | 160 | 0 |
| L | 120 | 90 | 30 |
| Total | 400 | 320 | 80 |
The M sold out halfway through the season, while 80 jumpers were left across S and L. If they sell at a 50% markdown, each one leaves a margin of €5 instead of €35: €2,400 less on a single style.
On top of that are the M sales lost because there was no stock. The problem was not how much Irene bought, but how she split it across sizes.
For next season, Irene needs four things:
- Use the data she already has in Shopify: sales, stock and products.
- Know how many units of each size she needs until the end of the season, before ordering.
- Allocate warehouse stock to her stores each week, based on what each one sells.
- Understand every quantity so she can adjust it when she knows something the data does not.
How does Datcisions address this?
Datcisions is an AI merchandise planning tool for fashion brands. It connects to your online store or your ERP, such as Shopify or Holded, reads your products, sales and stock, and turns them into purchase and allocation proposals by size that your team reviews before confirming.
For Irene's jumper, the difference is in the buying:
- Open-to-Buy calculates purchasing size by size until the end of the season. The quantity for each size is based on its sales, its stock, orders confirmed or in production in Datcisions and the expected delivery date.
- Each purchase quantity comes with a range. Open-to-Buy includes a minimum and a maximum with each proposal by size, based on sales history. If you choose a quantity outside that range, the tool flags it, and you decide the final quantity.
- Replenishment allocates what you already have. It proposes what to send to each store from the warehouse, size by size. You can reserve units and adjust quantities before confirming.
When does Nextail make more sense?
When your brand has 10 or more stores and your biggest challenge is allocating and moving stock across many locations.
If your priority is deciding what to buy, size by size, try Datcisions with a product you know well and see whether the proposal makes sense given your sales, stock and incoming orders.
Frequently asked questions about Nextail
Does Nextail work with Shopify?
Nextail connects to management, warehouse and point-of-sale systems; if you use Shopify, ask them about your situation.
What is the difference between a planning tool and a spreadsheet?
You can plan by size in a spreadsheet if you prepare the data and formulas yourself, product by product. Datcisions calculates proposals using your sales, stock and incoming orders, and you review them.
Can I try Datcisions before deciding?
Yes, free for 15 days: connect your online store or your ERP and review what you need to buy, size by size, until the end of the season. If you would prefer to see it with someone from the team, book a demo.
And if you are getting started with planning, How to plan purchasing and replenishment on Shopify when you sell fashion explains it step by step.
Sources
Consulted on 27 October 2026.