Blog · Wallet share and penetration
Use a short customer survey to establish category spending, supplier spending and the boundaries behind both amounts. This guide supplies question wording, a response table and checks against invoiced sales without treating missing answers as zero.
Share of wallet survey questions should establish what the customer bought in a defined category, how much they bought from your company, and which records support those answers. Ask about the same period and entities on both sides, then validate the supplier amount against your invoices. An unanswered spending question stays unknown.
The instrument below is for a business account review. It collects a usable denominator and evidence trail; the separate wallet calculation guide explains the general formula and roll-up.
Give the respondent a scope statement they can confirm or correct. For a fictional US packaging supplier, Lakefront Packaging, it could read:
Please report purchases of corrugated shipping boxes dated January 1 through September 30, 2026, for the US entities and sites listed on this form. Include purchases from all suppliers, including Lakefront Packaging. Use USD invoice amounts after returns, discounts and credits. Exclude sales tax, separately charged freight, tape, packing machinery and purchases by entities outside the list. Use invoice dates rather than payment dates.
Replace the category and dates for your business. Finance must prepare its matching net-sales extract on that basis; a customer's purchasing total and your recognized revenue may otherwise differ in timing. Keep those differences visible until reconciled.
The category scope register provides a matching place to document inclusions, exclusions and the scope version. Define the category before seeing the answers so disappointing shares do not prompt a narrower denominator.
Tell the customer why you are asking: to understand purchasing coverage and discuss service needs. State that responding is voluntary and explain the actual use of responses. Do not promise confidentiality arrangements your organization has not established.
Use the following question order. Each row collects a distinct fact, rather than combining spending, satisfaction and future buying intentions in one question. Pew Research Center's guidance on question wording supports clear, specific questions, one concept at a time, and response options that cover the reasonable answers.
| Field | Question wording | Response format |
|---|---|---|
| Scope confirmation | Does the scope statement describe the purchases you can report? | Yes; needs correction; cannot confirm. If corrected, record the change. |
| Entity coverage | Which listed entities and sites does your answer cover? | Confirm the list or mark included entities and sites. |
| Category total | What was your total spending in this category with all suppliers, including Lakefront Packaging, during the stated period? | Amount in USD; amount unavailable; prefer not to answer. |
| Range fallback | If an amount is unavailable, what lower and upper bounds can you support for that total? | Lower and upper amounts in USD; do not know; prefer not to answer. Skip when an amount was supplied. |
| Supplier spending | How much of that category spending was with Lakefront Packaging during the same period? | Amount in USD; do not know; prefer not to answer. |
| Evidence | What is the basis for the category total? | Purchasing records; accounts-payable records; informed estimate; other basis; do not know. |
| Basis check | Does the amount follow the invoice-date, credit, tax and freight rules in the scope statement? | Yes; no, with differences; cannot confirm. |
| Qualification | What omissions or uncertainties should we know about when interpreting the amounts? | Optional text describing limits. |
Keep response status separate from numeric fields. A respondent who declines to answer has provided information about availability, not a zero-dollar wallet. If only a range is provided, retain its bounds; do not silently use the midpoint as an observed total.
Before wider use, ask purchasing and finance respondents to complete the draft and explain how they found each answer. The Census Bureau's instrument-design standard describes pretesting with relevant respondents to expose comprehension, sequence and response problems. That is useful design guidance here, not a federal requirement imposed on your company survey.
Maintain an account ID, scope version, period, response date and evidence basis alongside the analysis columns. Use one approved response per account, category and period; archive superseded responses rather than adding them to the total.
Here is a fictional response review. All amounts relate to the scope above. The invoiced-sales column comes from the supplier's matching net-sales extract, not from replacing a survey blank with zero.
| A: Account | B: Reported wallet (USD) | C: Matched invoiced sales (USD) | D: Validation | E: Wallet share | F: Gap (USD) |
|---|---|---|---|---|---|
| A | 120,000 | 48,000 | Confirmed | 40.0% | 72,000 |
| B | 200,000 | 50,000 | Confirmed | 25.0% | 150,000 |
| C | 80,000 | 32,000 | Confirmed | 40.0% | 48,000 |
| D | Not provided | 20,000 | Not provided | — | — |
| E | 30,000 | 45,000 | Scope check | — | — |
Enter a numeric amount or leave the wallet cell empty in the workbook; the words shown above are display labels. With those columns, the row formulas are:
E2 = IF(AND(D2="Confirmed",ISNUMBER(B2),B2>0,ISNUMBER(C2),C2>=0,C2<=B2),C2/B2,"")
F2 = IF(ISNUMBER(E2),B2-C2,"")
Copy them down. Confirmation means a reviewer has checked the scope, dates and evidence, not merely that a response arrived. Account E remains unresolved because the supplier's own sales exceed the stated all-supplier wallet. Do not cap its share or erase the discrepancy.
Account A illustrates the invoice check. Its initial supplier-spend response differed from the sales extract:
| Reconciliation step | Amount (USD) |
|---|---|
| Customer's initial supplier-spend response | 47,000 |
| In-period invoice omitted from that response, confirmed during review | 1,000 |
| Corrected supplier-spend response | 48,000 |
| Matched net invoiced sales | 48,000 |
| Unexplained difference | 0 |
The check is 47,000 + 1,000 = 48,000, then 48,000 − 48,000 = 0. Preserve the original answer, the correction and the evidence. Agreement on your supplier amount improves confidence in alignment, but it does not independently prove the all-supplier total.
For the confirmed accounts, wallet totals are 120,000 + 200,000 + 80,000 = $400,000. Matched sales are 48,000 + 50,000 + 32,000 = $130,000. Their combined share is 130,000 / 400,000 = 32.5%, and their gap is 400,000 − 130,000 = $270,000. Row gaps also sum to 72,000 + 150,000 + 48,000 = $270,000.
That result describes the confirmed accounts. All-account sales total 48,000 + 50,000 + 32,000 + 20,000 + 45,000 = $195,000, leaving $65,000 outside the share calculation. Confirmed coverage is 3 / 5 = 60.0% of accounts and 130,000 / 195,000 = 66.7% of sales, rounded to one decimal place. Publish wallet evidence coverage beside the result.
For the broader account-review context, see the wallet share and penetration articles.
Bring your response workbook and matching account invoice export, including scope, periods and validation status. Covirage maps the columns, its tools compute and check the matched figures, and the external AI model explains the result with every figure traced to its rows. Create a free Covirage account and bring a sample of your own data.
See how this work fits share of wallet analysis.
Ask the purchasing or finance team that can see category spending across the entities and sites in scope. A local buyer may know one location well but cannot confirm a companywide total without access to the other purchasing records.
Prefer total category spending and spending with your company on a common basis. Amounts can be compared with invoices. If the customer only knows a range or percentage, preserve that response and its basis instead of converting it into an apparently exact amount.
Offer a range response and a clear option to decline. Leave the denominator unknown when neither is available. Your account revenue remains usable, but a missing customer wallet cannot support a wallet-share percentage or a dollar gap.
Refresh it when a comparable reporting period closes or when the account's category, entities or buying arrangements change. Retain the prior wording and scope version so a change in the survey does not look like a change in purchasing behavior.