Retail & CX metrics glossary
Attach rate measures how many sales leave with an add-on. Here is how to calculate it — and why it is entirely in your control.
Attach rate is the percentage of main products that leave the store with an additional item attached — an accessory, an insurance policy, an extended warranty, an installation or care service. Sell 100 phones and 30 cases alongside them, and your case attach rate is 30%. It is the metric behind the second line of the receipt: the one that grows revenue without a single extra visitor walking through the door.
Among all retail metrics, attach rate is the most peculiar — and the most controllable. Traffic depends on location and marketing; conversion depends partly on price and stock. But attach is a metric that only exists if the seller offers: no customer walks into a store asking for a screen protector, an extended warranty or the matching socks. This page covers the formula, a working calculator, benchmarks by category, how attach relates to UPT and average ticket, and what actually moves it.
Attach rate
Attach rate = (add-on items ÷ main products sold) × 100
add-on items = accessories, warranties, insurance or services sold alongside a main product in the period · main products sold = units of the primary product sold in the same period
Attach rate calculator
A phone retailer sells 1,400 handsets in a month, and alongside them 476 add-on items — cases, screen protectors, earbuds and extended warranties. Attach rate = (476 ÷ 1,400) × 100 = 34%. Broken down per store, the range runs from 18% to 51% on the same products, same prices and same customer profile — which is the first clue that attach is about seller behavior, not about the market.
What is a good attach rate?
Attach benchmarks vary sharply by category, because the natural add-on and its price point vary. As a rough map from industry practice:
| Phone accessories (case, screen protector, earbuds) | 20–40% |
|---|---|
| Extended warranties & insurance | 5–15% |
| Footwear + socks, belts or care products | 10–25% |
| Appliances & electronics + installation or service | 15–30% |
Ranges reflect common industry practice, not a single audited source — product mix, price architecture and commission policy move these numbers a lot. A chain that pays commission on warranties will attach more warranties. Use as orientation, then benchmark store against store inside your own network.
Attach rate by category: where the add-on lives
In phone and electronics retail, the classic attach items are the case, the screen protector, the charger and the earbuds — low-ticket, high-margin, and genuinely useful, which makes them the easiest offer in retail. In appliances and big-ticket electronics, attach shifts to extended warranty, insurance and installation: fewer units, but each attach is worth many times the accessory ticket.
In footwear, the natural attach is socks, insoles, belts and cleaning or care products; in fashion, belts, scarves and complementary pieces that complete the look. Every category has its native add-on — and in almost every one, the add-on carries a higher margin percentage than the main product. That is why a few points of attach often matter more to store profitability than a few points of traffic.
Attach rate × UPT × average transaction value
The three metrics form a chain. Every successful attach adds a unit to the transaction, which lifts UPT (units per transaction); the extra unit adds revenue, which lifts ATV (average transaction value). Same traffic, same conversion rate — and the store sells more, at zero acquisition cost, usually at the best margin in the house.
The difference between them is diagnostic power. UPT and ATV tell you the size of the basket; attach rate tells you whether a specific, nameable behavior happened — was the warranty offered on this TV, the protector on this phone, the socks with these sneakers? When basket metrics stall, attach by item is where you look to find out which offer stopped happening.
How to raise attach rate: it is a frequency problem, not a talent problem
The levers are known. Offer at the right moment — after the main product decision is made and before payment, when the customer's mind has already said yes. Build kits and bundles so the add-on is part of the proposal, not an afterthought at the register. Give sellers a concrete closing script: not 'do you want anything else?', but 'this phone deserves the protector — want me to apply it now?'.
But underneath every lever sits the same fact: attach is not luck and it is not customer profile. It is offer frequency. A seller who offers the add-on in 9 out of 10 sales will have attach; a seller who offers in 1 out of 10 will not — with the same products, the same prices and the same customers. Whoever does not offer has zero attach by definition. Which raises the uncomfortable management question: in your stores, how often is the offer actually being made? Most chains coach the script in training and then never observe whether it happens on the floor.
Attach rate is not luck. It is offer frequency.
Cognifyze measures the sales conversation itself — with consent and without identifying any shopper — so attach stops being a number you inherit and becomes a behavior you manage: in what share of interactions the add-on was actually offered, at which moment, with which words, and what happened when it was. The gap between attach rate and offer rate is where the money is.
In measured deployments, making the interaction visible moved same-store conversion from 51.5% to 79.5% (+28pp, p<0.001), with 383% ROI and payback in 1.4 months.
Find out how often your team actually offers — book an executive diagnostic.
Related metrics and guides
Attach rate — frequently asked questions
What is a good attach rate?
It depends on the add-on. Phone accessories commonly run 20–40%, extended warranties and insurance 5–15%, footwear add-ons 10–25%, installation and services on appliances 15–30%. The more useful comparison is internal: on identical products and prices, the spread between your best and worst store is your real opportunity.
How is attach rate calculated?
Divide the number of add-on items sold by the number of main products sold in the same period and multiply by 100. Measure it per add-on category (cases, warranties, services) rather than as one blended number — a strong accessory attach can hide a warranty attach near zero.
What is the difference between attach rate and UPT?
UPT (units per transaction) counts all items in the basket, whatever they are; attach rate ties a specific add-on to a specific main product. UPT tells you the basket grew; attach tells you which offer made it grow — which is what you need to coach a team.
Why is my attach rate low?
In the overwhelming majority of cases, because the offer is not being made — not because customers refuse it. Nobody enters a store asking for a screen protector or an extended warranty; attach only exists when the seller proposes it. Before changing the product or the price, measure how often the offer actually happens on the floor.
Does pushing add-ons hurt the customer experience?
Pushing does; offering does not. A relevant add-on proposed at the right moment — the protector applied before the phone leaves the store, the care kit with the leather shoes — is perceived as service, not pressure. What erodes experience is the generic 'anything else?' at the register, which is also the offer with the lowest attach.