Why onboarding fails more often than it should
Most botched onboardings don’t fail because a firm forgot a document — they fail because nobody wrote down who was responsible for producing it, or by when. A client hands over three months of bank statements and assumes that’s onboarding done; the firm assumes the client will mention payroll, a second location, or a switch in POS systems unprompted. Neither assumption survives contact with a real business.
The second failure mode is sequencing. Firms that request banking credentials or prior tax returns before an engagement letter is signed put themselves in an uncomfortable spot if the relationship doesn’t move forward — and clients who are asked for everything in one email, with no sense of what’s urgent versus what can wait, tend to send back whatever’s easiest to find first, not what you actually need first.
The list below groups what to collect by category, marks what should be confirmed before you touch a single transaction versus what can reasonably arrive during the first month, and explains why each item earns its place — so you can hand it to a client with a reason attached, not just a demand.
The complete checklist, by category
Entity & tax documents
- IRS EIN confirmation letter (CP 575 or 147C). Why you need it: confirms the exact legal name and identifier the IRS has on file, which needs to match your ledger and any filing you touch later.
- Formation documents — articles of incorporation or organization, partnership agreement. Why you need it: establishes entity type, ownership split and fiscal year-end, all of which change how equity and distributions get booked.
- Most recent filed business tax return. Why you need it: gives you real beginning balances and confirms which accounting method the client has actually been using, regardless of what they tell you.
- State or local business license and any sales tax permit. Why you need it: identifies which jurisdictions you’re responsible for tracking, so a filing obligation doesn’t surface as a surprise later.
Banking & cards
- A list of every operating account, with bank name and last four digits. Why you need it: an account the client forgets to mention becomes an unreconciled gap discovered months from now, not today.
- Read-only accountant access to online banking, or a signed letter authorizing you to request statements directly. Why you need it: removes a recurring dependency on the client remembering to forward a PDF every cycle.
- Business credit and charge card statements for the trailing twelve months. Why you need it: personal-card business spend is one of the most common sources of a misclassified expense.
- A voided check or bank letter confirming account ownership. Why you need it: confirms the account genuinely belongs to the entity, not a related person or a former partner.
Payroll
- The most recent payroll register or summary report. Why you need it: lets you map payroll expense categories correctly before the first close, instead of reclassifying after the fact.
- Payroll provider name and reporting access. Why you need it: the summary is needed for classification even though running payroll itself sits outside a bookkeeping engagement.
- Current state unemployment insurance rate notice. Why you need it: this rate changes yearly and directly affects payroll tax expense; an outdated rate quietly understates cost.
- A list of contractors likely to cross the annual reporting threshold. Why you need it: flags 1099 exposure the client may not have thought to mention on their own.
Sales channels & POS
- Point-of-sale or storefront platform name and reporting access. Why you need it: settlement reports rarely match bank deposits one-to-one, and you need the source report, not the deposit total.
- Merchant or payment processor account statements. Why you need it: fees, refunds and holdbacks each need their own line, not a net-deposit guess.
- A summary of where sales tax is collected, if the client sells across state lines. Why you need it: multi-jurisdiction exposure is easy to miss at kickoff and expensive to unwind a year in.
- Whatever inventory or cost-of-goods method the client currently uses, if any. Why you need it: determines whether you’re building a balance sheet item from nothing or reconciling an existing count.
Prior-year records
- Prior-year balance sheet and profit and loss statement. Why you need it: beginning balances have to tie to something concrete; rebuilding them from bank statements alone almost always misses the last few adjusting entries.
- Export from the prior bookkeeper or software, in whatever format exists. Why you need it: even a messy export carries account history that would otherwise have to be reconstructed by hand.
- A fixed asset list with purchase dates and original cost. Why you need it: a depreciation schedule that restarts from zero overstates current-year expense.
- Any outstanding loan or line-of-credit schedules. Why you need it: lets you split principal from interest correctly starting in month one instead of estimating a split.
Access & permissions
- The name of whoever is authorized to approve your monthly deliverable. Why you need it: naming this person now heads off the most common cause of a scope dispute later.
- Anyone else at the business who needs visibility into the engagement. Why you need it: firms routinely discover mid-year that a partner or investor was supposed to be seeing reports all along.
- Confirmation of who can verify your access if a bank or tax authority calls to check. Why you need it: saves a stalled call later if you ever need to confirm your role on the client’s behalf.
- A named backup contact at the client’s business. Why you need it: the primary contact taking a week off shouldn’t stall a close that’s already in progress.
Engagement paperwork
- A signed engagement letter defining scope. Why you need it: this single document prevents more disputes than any other item on this list — put boundaries in writing, not just in conversation.
- A signed W-9 from the client, if you invoice as a contractor rather than a firm. Why you need it: needed for your own 1099 reporting at year-end.
- A written fee agreement and billing method. Why you need it: keeps a pricing conversation from happening informally in the middle of an engagement.
- A confidentiality or data-sharing acknowledgment. Why you need it: sets expectations about how documents are handled before the client ever uploads one.
What to ask before kickoff vs. during the first month
Not everything needs to land in your inbox on day one. Splitting the list this way keeps the initial ask short enough that a busy client actually responds to it.
Confirm before kickoff
- Entity identity, formation documents and prior-year returns
- The full list of bank and card accounts in active use
- Prior-year balance sheet, P&L and any prior software export
- Signed engagement letter, fee agreement and named approver
Collect during the first month
- Payroll provider access and the current unemployment rate
- POS or storefront reporting access and merchant statements
- Sales tax jurisdictions, if they weren’t obvious at kickoff
- A backup contact, once you’ve seen who actually responds
Common mistakes worth naming
- Treating the engagement letter as a formality. A verbal agreement about scope is the single most common source of a fee dispute six months in — put boundaries in writing before the first document request goes out.
- Asking for everything in one long email. A client facing thirty line items in a single message tends to answer the easy ones and quietly ignore the rest. Splitting the ask by category, or by before/first-month timing, gets a more complete response.
- Assuming the client will mention business changes unprompted. A new location, a new bank account, or a switch in payment processor rarely gets flagged voluntarily — it has to be asked about directly, and asked about again next month.
- Skipping the backup contact. Onboarding often stalls entirely when the one person who was responding goes on leave and nobody else at the business knows what’s outstanding.
Printable summary
| Category | When to ask | Note |
|---|---|---|
| Entity & tax documents | Before kickoff | Needed to confirm legal identity and starting method. |
| Banking & cards | Before kickoff | The account list gates everything reconciled after it. |
| Payroll | First month | Classification only — administering payroll stays with the provider. |
| Sales channels & POS | First month | Confirm the platform before the first pack; statements arrive monthly. |
| Prior-year records | Before kickoff | Beginning balances depend on it — chase this hardest. |
| Access & permissions | Before kickoff | A named approver and backup contact, agreed in writing. |
| Engagement paperwork | Before kickoff | Signed before the first document is requested. |
Running this checklist in Cohesio
Doing this across email threads and a shared drive means retyping the same request list for every new client and hoping nothing gets skipped. Cohesio’s client intake turns a checklist like this one into a template: pick a client type, confirm the requirements that apply, and send a single branded link. The client sees a short, plain-language list with a due date; you see what’s outstanding without opening an inbox.