End-of-Year Invoicing Checklist: Close Your Books Right

Year-end is when loose invoicing habits become expensive: revenue slips across tax years, bonuses miss targets, and tax filings disagree with what clients think they paid. A disciplined December close protects everyone, especially you. This checklist covers the invoicing side; for the tax moves with a December 31 deadline, see our year-end tax planning guide.

Two weeks before year-end

Publish a billing cutoff

Tell clients and your team the last day December work can go on this year's invoices. Tie milestone and progress billings to signed acceptance where possible.

Chase open receivables

Run your follow-up strategy early; client accounts payable teams slow down over the holidays.

Verify client details

Tax IDs, billing addresses and PO numbers: errors found on December 31 are painful. Apply your onboarding standards to older accounts with missing details.

Final week

Issue legitimate December invoices only

Do not bill early for work you have not done to inflate this year's numbers; that invites disputes and damages trust.

Apply credits cleanly

Year-end is a common moment for true-ups. Use credit notes rather than editing invoices you have already sent.

Currency check

Invoice in the agreed currency, and note the rate if you convert for your own reporting (currency).

Discounts and promotions

If you run holiday discounts, model the margin with the discount calculator. If you offer clients a discount for paying a full year in advance, our discount timing guide shows how to work out whether it pays.

Does a December invoice count as this year's income?

It depends on your accounting method, not on the date printed on the invoice. Under the cash method, income counts in the year you receive it or it is made available to you. Under the accrual method, it generally counts when you have earned the right to it and the amount is fixed, whether or not the client has paid (IRS Publication 538).

Worked example: you finish a $4,000 project on December 18, 2026 and invoice it that day on Net 30 terms, so it is due January 17, 2027. If the client pays on January 12, a cash-method business reports the $4,000 in 2027; an accrual-method business reports it in 2026. Invoicing on January 4 instead would not change the accrual result, because the work was done in 2026. Ask your accountant which method you use before you make timing decisions.

Form W-9 and Form 1099-NEC

If you are...	What to do	Rule (payments made in 2026)
A contractor billing US business clients	Send your Form W-9 with your December invoices so clients have your taxpayer ID	Clients generally file Form 1099-NEC if they paid you $2,000 or more for services
A business that paid contractors	Collect a Form W-9 from each contractor now	File Form 1099-NEC for each nonemployee paid $2,000 or more; copies to the recipient and the IRS by January 31, the next business day if it falls on a weekend

Source: IRS Instructions for Forms 1099-MISC and 1099-NEC (revision 12/2026, accessed 28 October 2026). The $600 threshold applied to earlier years, and the IRS says the $2,000 figure may be adjusted for inflation from 2027.

Two points that cause confusion:

Card and payment app payments are not reported on Form 1099-NEC. If a client pays you by card or through a payment app, any reporting is on Form 1099-K from the payment company, not from your client.
Income below the threshold is still taxable. The IRS's Form 1099-K page says you must report your income whether or not you get a form, so reconcile your own invoices and payment records rather than waiting for 1099s.

This is general information, not tax advice. Last reviewed 28 October 2026.

After December closes

Reconcile bank and receivables

Match partial payments to invoices, and decide which old balances you will stop pursuing. If you use the cash method you generally cannot deduct unpaid fees as a bad debt, because that income was never reported (IRS Topic 453). Record a credit note or cancel the invoice so your records match reality; the bad debt entry covers the accrual side.

Back up everything

Save the year's invoice PDFs and data exports as set out in our backup strategy.

Preview the January schedule

Review recurring invoices around the holidays, and confirm your payment terms still fit next year's cash plan.

December invoicing timeline

These dates are a suggested plan for a calendar-year business, not legal deadlines.

Action	Suggested timing	Why
Send December retainer and recurring invoices	December 1	Gives clients the whole month to pay
List all finished but unbilled work	December 1 to 5	Nothing earned this year should be forgotten
Send all outstanding invoices	By mid-December	On Net 30, an invoice sent December 15 is due January 14; one sent December 28 is not due until January 27
Final follow-up on overdue invoices	December 15 to 22	Before client offices close for the holidays (December 25, 2026 is a Friday)
Send your W-9 to clients; collect W-9s from contractors	December	Needed for Forms 1099-NEC due February 1, 2027
Review old balances and credit notes	December 28 to 31	Records match what you expect to collect

Step-by-step: end-of-year invoicing flow

Step 1: Identify all unbilled work as of December 1

Pull project lists, time records, retainer renewals and milestones reached. Anything finished but not invoiced should be billed in December, so nothing earned is forgotten and your revenue figures are complete.

Step 2: Send a year-end statement to active clients

A one-page summary of the year (invoices issued, amounts paid, any balance owed) helps clients reconcile their records and surfaces anything overlooked.

Step 3: Make a final collection push on overdue invoices

Send firm, polite follow-ups early in December. For example: "Year-end note: invoice INV-0142 from 3 November is still outstanding. So we can both close the year cleanly, please arrange payment by 18 December."

Step 4: Send your W-9 to clients who may file a 1099

If a US business client paid you $2,000 or more for services in 2026, they generally need your taxpayer ID to file Form 1099-NEC. Sending your W-9 with the December invoice saves a January request.

Step 5: Review receivables you will not collect

Decide case by case, keep a record of your collection attempts, and talk to your accountant about the tax treatment. The cash-method rule above means writing off an unpaid invoice usually gives a cash-basis business no deduction.

How InvoiceQuickly helps at year-end

Recurring invoices (Pro): schedules create invoices as drafts for review or send them automatically. A schedule cannot be edited after it is created, so to change a December amount, set up a new schedule.
Credit notes (Pro): issue one against a sent invoice for a year-end true-up or a balance you have agreed to waive.
Numbering: numbers carry on across the new year and cannot be reset to a lower number, which keeps one continuous series.
Client details: you can store a client's tax ID, and it is copied to new invoice PDFs; check the saved IDs and PDF before sending.
Records: the invoice CSV export (Pro) gives you the year's invoices in one file. Download PDFs one at a time for your year-end archive.

Final takeaway

Year-end is an integrity moment, not a revenue hack. Bill what you earned when you earned it, communicate cutoffs early so nobody feels ambushed, and close the books once, correctly.

Frequently asked questions

When should I send my last invoice of the year?

As early in December as the work allows. On Net 30 terms, an invoice sent December 15 is due January 14, so even a prompt payer settles in the new year. If you use the cash method, that payment is next year's income.

Do clients send me a 1099-NEC if they paid me through PayPal or Stripe?

No. Payments by card or through a payment app are not reported on Form 1099-NEC; any reporting is on Form 1099-K from the payment company. Clients who paid by bank transfer or check generally file Form 1099-NEC if they paid you $2,000 or more for services in 2026.

When can I write off a bad debt for tax purposes?

If you use the cash method, you generally cannot deduct unpaid fees at all, because the income was never reported. If you use the accrual method, a business bad debt is deducted for the year it becomes worthless, under the rules in IRS Topic 453. Your accountant can confirm the treatment.

Should I close my books on December 31 or later?

Your tax year ends December 31 if you use a calendar year, but many businesses take a few weeks in January to finish reconciling December. Pick one closing routine and use it every year.

What about January invoices for December work?

Under the accrual method, December work is generally this year's income however late you invoice it. Under the cash method, income counts when you are paid. Either way, invoice promptly so payment is not delayed.

Close the year with invoices you can defend in an audit. Start free.