How to Improve Address and Phone Number Quality in COD Orders

A failed delivery on a prepaid order is annoying. A failed delivery on a cash on delivery order is worse, because the store already paid for packing, shipping, and a courier attempt, and collects nothing at the end of it. When the reason is a wrong address or a phone number nobody answers, that cost was avoidable before the parcel ever left the warehouse.

This is not a rare edge case. Wrong or incomplete addresses and unreachable phone numbers are commonly reported reasons for failed deliveries across courier networks. COD makes the problem worse for a simple reason: the customer has not paid anything yet, so there is nothing pulling them back into the process if the courier cannot reach them. A prepaid customer usually has a stronger incentive to stay reachable because money is already committed. A COD customer who does not answer may feel less urgency, because no payment has been made yet.

This article covers how to recognize the problem, why it shows up more on COD orders specifically, and what to fix first.

Signs You Have an Address or Phone Data Problem

A few patterns are worth checking before assuming this is happening at all:

• Your COD failed-delivery or return-to-origin rate is meaningfully higher than your prepaid rate, on the same routes and courier.
• Support tickets mention the courier "couldn't reach the customer" or "couldn't find the address."
• A visible share of OTP codes fail to deliver, time out, or get entered incorrectly on the first attempt.
• The same customer places several orders that each fail for a similar reason.
• Orders arrive with obviously incomplete address fields, such as no building or apartment number in a dense urban address, or a phone number with the wrong number of digits for its country code.

None of these alone proves a data-quality problem, but a pattern across several of them usually does.

Why This Happens More on COD Orders

• There is no payment step to catch a typo. On a prepaid order, a customer often re-enters or confirms details near the payment step, and a payment failure sometimes prompts a second look at the form. COD checkout can complete in one pass, with no equivalent checkpoint.
• The order feels lower-commitment, so less gets double-checked. Customers filling out a COD order sometimes move faster, because nothing is being charged yet. Fast checkout is good for conversion and bad for data accuracy at the same time.
• Fake or junk orders lean on COD specifically. A fraudulent or prank order is easiest to place where no payment method needs to be valid. Junk phone numbers and copy-paste addresses are a common signature of these orders, not just of honest mistakes.
• International and mixed-format fields cause confusion. A phone field that does not clearly separate a country code from the rest of the number produces numbers that look complete but are not dialable, especially on stores serving more than one market.
• Autofill can overwrite a correct field with a stale one. Browser and form autofill occasionally repopulate an old address or a family member's phone number when a customer is checking out from a saved profile on a shared device.

Fix 1: Verify the Phone Number Before the Order Is Confirmed

This is the single most direct fix, because it addresses the problem at its source rather than after the fact. OTP verification sends a one-time code to the phone number entered at checkout, and the order only proceeds once that code is confirmed. A wrong, mistyped, or fake number simply does not receive the code, which stops the order before a courier is ever dispatched to an unreachable customer.

This does not fix address quality directly, but it removes the single most common reason a courier cannot resolve a bad address either: if a driver cannot find the building, an unreachable phone number is what turns that into a failed delivery instead of a five-minute phone call for directions. A verified, working phone number turns many address problems from "failed delivery" into "delivery that took one extra phone call."

For the full mechanics of how this fits into a layered COD defense, see how OTP verification helps secure COD orders.

Fix 2: Exclude Postal Codes With a Track Record of Problems

If failed deliveries are concentrated in specific postal codes rather than spread evenly, a blanket fix aimed at every order is the wrong tool. Postal-code exclusion, available in the fraud-protection area of Progus COD Form & OTP SMS alongside blocking by email, phone, and IP address, lets a store remove COD as an option for the specific areas with a documented pattern of failed deliveries, without restricting an entire country or region that mostly delivers fine.

Base this on your own delivery data, not on assumptions about which areas seem risky. A postal code with three failed deliveries out of five orders is a different case from one with three failed deliveries out of five hundred.

For broader COD visibility shaping, postal codes can also be part of Smart COD Rules; the fraud-protection area is better suited to known problem patterns and repeat offenders.

Fix 3: Add Friction for the Order Patterns That Correlate With Bad Data

Not every risky pattern needs an outright block. Visibility rules let a store change COD availability for specific order patterns rather than treating every order the same. In some cases that means hiding COD entirely and requiring prepaid checkout; in others it means keeping COD available only for customers or carts that match safer conditions. A cart-value threshold is the most common example: above a certain order value, requiring prepaid checkout removes the highest-cost failures from the COD pool entirely, since a failed delivery on an expensive order wastes more than one on a cheap item.

Customer tags work in the other direction. A tag applied after a customer's address or phone number caused a failed delivery can restrict COD for that customer going forward, while a tag for a customer with a clean delivery history keeps their experience friction-free. For the full mechanics of combining these conditions into a single rule, including how "show" and "hide" conditions interact, see Smart COD Rules: Country, ZIP, Cart Value, Customer Tags.

Fix 4: Block Repeat Offenders Directly

Some customers or numbers do not need a rule that adds friction. They need to be blocked. The fraud-protection area supports blocking by email, phone number, and IP address, plus limiting how many orders the same customer can place in a given window. This is the right tool once a specific phone number or address has already produced more than one failed delivery, rather than waiting for a pattern to repeat a third or fourth time.

Fix 5: Reduce Entry Errors at the Point of Checkout

Beyond what the app configures directly, general form design reduces how often a customer submits bad data in the first place, regardless of platform:

• Explain why the phone number is needed. Baymard's checkout research found that 14% of online shoppers would never provide their phone number to an online store, while 39% of benchmarked ecommerce sites require a phone number without explaining why. For COD orders, the explanation matters: the phone number is needed so the courier or store can resolve delivery issues, not for unrelated marketing.

• Separate the country code from the rest of the phone number, so a customer cannot submit a number that looks complete but is missing or duplicating the country prefix.
• Show a short format hint near the address and phone fields rather than only rejecting bad input after submission.
• Make apartment, unit, or building number fields visible by default rather than hidden behind an optional toggle, since these are the details most often missing from failed-delivery addresses.
• Watch for autofill silently overwriting a field the customer already corrected, particularly on shared devices or saved browser profiles.

These are general checkout-design practices rather than a specific claimed setting inside COD Form & OTP SMS. If your store's current form does not support one of them, that is a theme or form-configuration question worth raising alongside the fraud-protection settings above.

What to Do When an Order Already Has Bad Data

Prevention will not catch everything. For orders that already look suspect before dispatch:

• Hold high-value or already-flagged orders for a manual confirmation call or SMS before packing them, rather than shipping first and finding out at delivery.
• Give support a clear, short script for confirming an address and callback number, so this does not depend on one person's judgment.
• Do not silently guess at a corrected address on the customer's behalf. Confirm it, or hold the order.
• Log the outcome against the customer profile, so a repeat problem shows up as a pattern rather than resetting every time.

Address and Phone Quality Checklist

Your address and phone data controls are in good shape when:

• OTP verification is active on COD checkout, so an unreachable or fake phone number stops the order before dispatch
• postal codes with a documented pattern of failed deliveries are excluded, based on your own data rather than assumptions
• a cart-value threshold moves your highest-cost orders to prepaid checkout
• customer tags distinguish a clean delivery history from a flagged one
• repeat offenders are blocked by email, phone, or IP rather than re-evaluated order by order
• checkout fields separate country code from phone number and keep address sub-fields visible
• a manual-confirmation process exists for orders that look risky before they are packed

Mistakes That Turn Bad Data Into Failed Deliveries

• Treating every failed delivery as fraud. Most bad address and phone data comes from rushed or careless entry, not malicious intent. Punishing every customer the same way a fraud case would be punished creates unnecessary friction for people who made an honest mistake.
• Fixing the postal code problem with a country-wide rule. If the pattern is concentrated in specific areas, a country-level restriction blocks far more good orders than it needed to.
• Shipping first and confirming later. Once a parcel is with the courier, a bad address or number turns into a failed delivery no matter how quickly support notices it. Catching the problem before dispatch is always cheaper than catching it after.
• No process for repeat offenders. A customer whose address or phone number has already caused one failed delivery is a known risk, not a fresh case, the second time it happens.

Final Thoughts

Bad address and phone data on COD orders is rarely a single dramatic failure. It is a small, steady leak, one failed delivery at a time, each one absorbing packing, shipping, and courier cost with no revenue at the end. The fix is not a single setting but a layered one: verify the phone number before dispatch, exclude the postal codes with a real track record, add friction for the order patterns that correlate with failure, and block the repeat cases outright.

For the full picture of how these layers work together with fraud detection more broadly, see Progus' COD fraud and return abuse playbook. If cash on delivery is part of your Shopify checkout, Progus COD Form & OTP SMS covers the verification and rule-building side of catching this before it costs you a delivery.