PingtailNew client onboarding document checklist
What to collect from a new bookkeeping or tax client in the first week, in the order that unblocks your work. IDs, prior returns, bank details.
A new client is most willing to send you documents in the first week. After that, attention goes back to running the business. So ask for everything in that week, in one organised request, in an order that lets you start work before the last item arrives.
This new client onboarding document checklist is written for a US firm taking on a small business client for bookkeeping, tax or both, ordered by what unblocks your work first. Short notes for firms in the United Kingdom and India are near the end.
Which documents come first, and why?
Four groups, in the order they unblock work.
| Group | What it unblocks | Aim to have it by |
|---|---|---|
| Engagement and identity | Permission to start, and to bill | Day 1 or 2 |
| Entity and tax registration | Setting up the client correctly in your systems, and knowing which filings exist | Day 3 |
| Access and statements | The catch-up work itself | Day 5 to 7 |
| Questions | Decisions about how you will keep the books | Day 7, often in one call |
Send everything in one request on day 1, but tell the client the order: "If you only have ten minutes today, please do the first three items."
1. Engagement and identity
- Signed engagement letter. Every page, signed and dated. Ask: "Please sign and date the engagement letter and send back every page. We cannot start work until we have it."
- Photo ID of the owner or the person who signs. A clear photo of the front and back of a driver's license or state ID, not expired. If you e-file returns you need to know who the taxpayer is.
- Who is who. Name, email and phone for the person who decides, the person who sends documents and the person who pays your invoice. Mira Chen owns Bright Dental, but Tom Reed, the office manager, has the bank login.
- Exact legal name and any trade name, as they appear on IRS letters.
2. Entity and tax registration documents
- EIN letter. The IRS letter that assigned the employer identification number (CP 575), or the 147C letter that confirms it. It shows the exact legal name the IRS has on file. If the client cannot find it, the EIN on a past return will do for the first week.
- Formation documents. Articles of organization or incorporation, and the operating agreement or bylaws. You need the formation date, the state, and for a business with several owners, each owner's percentage.
- Tax classification. If the business is taxed as an S corporation, ask for the IRS acceptance letter for the Form 2553 election. "We are an LLC" describes the legal form, not how the business is taxed. The prior return settles it.
- Prior tax returns. The most recent business return, federal and state, every page, including depreciation schedules. Two or three years is better. Ask: "A PDF from your previous preparer is best. Please send the whole return, not only the first pages."
- State registrations. State tax account numbers for sales tax, payroll withholding and unemployment insurance, and the filing frequency for each. Check the rules for each state where the client operates.
- Recent IRS or state notices. Ask directly. Clients rarely mention these.
3. Access and statements
Access first, documents second. With your own login, you never have to request that document again.
- Accounting software access. Ask the client to invite you as an accountant user from inside the software. Add the sentence: "Never send us your own username or password."
- Last year's books. If the client is changing software or the old file is gone: the profit and loss and balance sheet for the last two full years, the year-end trial balance, the general ledger export, and the chart of accounts. The closing balance sheet should agree with the last filed return.
- Bank and card statements for the catch-up period. Every business account, every month from the last reconciled date to today, as full PDF statements. Give the exact range: "Statements for January to August 2026 for checking ending 4417 and the card ending 2203." One PDF covering several months is fine if no month is missing. The bank statement checklist covers what makes a statement usable.
- View-only bank access. Many banks let a business add an accountant with view-only rights. That ends the monthly statement request for good.
- Payroll provider reports. Accountant access at the provider if available. If not: year-to-date payroll summaries, the Forms 941 filed this year, and last year's W-3.
- Loan agreements. The agreement and the latest statement for each loan and line of credit: amount, rate, term, start date and current balance, so payments can be split into principal and interest.
- Fixed asset list. The depreciation schedule from the prior return is usually the best one.
- Sales tax filings. The last few returns filed. They show the filing frequency, and whether the liability in the books agrees with what was filed.
- 1099 vendor list. The contractors the client pays, with a Form W-9 for each. If W-9s are missing, start collecting now; the 1099 filing deadline is the end of January.
- Regular vendors and customers. A short list, with a few words on each.
Give every item a sentence that says what to send, for which dates, and where to find it. "Bank statements" gets you three screenshots. "Full PDF statements for January to August 2026, from the Statements section of your online banking, every page" gets you what you need.
4. Questions to ask, not documents to collect
Some of the most useful information is in nobody's filing cabinet. Ask these as short answers in the request, or in a call at the end of week one.
- When does your business year end?
- Do you report on the cash or accrual basis?
- Which bank accounts, cards and payment services does the business use, including the ones you rarely touch?
- Does anyone pay business costs from a personal account, or personal costs from the business account?
- Do you take cash? How is it recorded, and how often is it deposited?
- Do you hold inventory? How do you count it, and when was the last count?
- Who runs payroll, and how often? Do you pay contractors as well as employees?
- In which states do you have employees, an office, or regular sales?
- What was the last month your books were reconciled?
- Who was your previous accountant, and may we contact them?
- Which reports do you read, and what do you want to know each month?
Notes for UK and India firms
United Kingdom
UK accountancy firms fall under the anti-money-laundering regulations, supervised by a professional body or by HMRC. Before work starts you must carry out customer due diligence: identify the client and verify that identity from reliable sources, identify the beneficial owners of a company, assess the risk, and keep records. In practice that means photo ID and a recent proof of address for each individual, and for a company, the Companies House details and the people with significant control. Follow your supervisor's guidance for the exact evidence.
You also need the Unique Taxpayer Reference, the VAT number if registered, the PAYE reference if there are employees, and authorisation to act as the client's agent with HMRC.
India
Start with the PAN of the business and of its proprietor, partners or directors, and the GST registration certificate with the GSTIN if registered. Then the TAN if the business deducts tax at source, the incorporation documents or partnership deed, and prior income tax returns with their computations. For GST work, ask for the filed returns for the period you are taking over.
Portal access should be granted the way the portals provide for, not by emailing a password. Thresholds and requirements change, so check the current rules.
Printable new client onboarding document checklist
- Signed engagement letter, every page
- Photo ID of the owner or signer
- Contacts: who decides, who sends documents, who pays
- Exact legal name and trade name
- EIN letter (CP 575 or 147C)
- Formation documents and ownership percentages
- S corporation election acceptance, if it applies
- Prior business tax returns, federal and state, every page
- State tax account numbers and filing frequencies
- Any open IRS or state notices
- Accountant access to the accounting software
- Prior financial statements, trial balance, general ledger, chart of accounts
- Bank and card statements for the whole catch-up period
- View-only bank access, if the bank offers it
- Payroll provider access or reports
- Loan agreements and latest statements
- Fixed asset list or depreciation schedule
- Recent sales tax filings
- 1099 vendor list with W-9s
- Regular vendors and customers list
- Answers to the onboarding questions
Questions
Should I send one long request or several short ones?
One request, with the order made clear inside it. Separate emails get lost in the client's inbox, and with five threads open nobody can see how much is left. Mark as required only what you cannot start without, so the client sees a short must-do list and a longer when-you-can list.
What if the previous accountant will not hand over the files?
The client, not you, should make the request in writing. What a client is entitled to depends on professional rules and on the state, so do not promise more than they can demand. Meanwhile, the filed returns and the bank statements are enough to rebuild opening balances. For items that stay open, use a fixed follow-up workflow.
How far back should catch-up statements go?
To the last date you can trust: the closing date of the last reconciliation that agrees with a filed return. If nobody knows, start from the first day of the current tax year and agree the opening balances to the prior return.
Doing this with Pingtail
Pingtail has a new client onboarding checklist for the United States, the United Kingdom and India, plus a UK checklist for identity checks under the anti-money-laundering rules. Items can be files, yes or no questions or short answers, so the documents and the questions above go out in one request with one link. You can add or remove items for one client and save the result as your own template. The client needs no account, can photograph an ID with a phone camera, and every file is encrypted before it is stored. See how onboarding works. You can try it on yourself first: send a test request to your own email and upload the wrong file on purpose.