Bookkeeping for your US LLC step by step: keep it simple and clean

7 years. Running your LLC's bookkeeping is simpler than it looks. Tools, monthly structure, reconciliation, currencies and year-end close for non-residents.

The IRS requires you to keep an LLC's bookkeeping records for at least 7 years, and a Form 5472 with no books behind it starts at a 25,000-dollar penalty. Breathe: at Exentax this is routine, we bring you up to date and the next review closes in one round, no drama.

Keeping the books for a US LLC scares people more than it should. Most non-resident owners come from a model where an accountant asks for paperwork, files quarterly returns and you barely touch anything. With a US LLC the model is different: day to day operations are run by you with modern tools, and at year end an orderly bookkeeping translates into a clean filing with no surprises.

At Exentax we walk hundreds of clients through this every year. This guide summarizes how to organize the bookkeeping of your LLC step by step, without shortcuts but without making it more complicated than it needs to be.

What bookkeeping is and why it matters

Bookkeeping is, simply, the orderly recording of every economic movement of your LLC: income, expenses, transfers between accounts, owner draws and ending balances. It is not the same as the tax return: the return uses the data from your bookkeeping, but bookkeeping lives all year long.

Clean bookkeeping gives you three things: compliance (Form 5472, 1120 pro forma and, in some states, additional reports), control (knowing how much you really earn after expenses) and a paper trail in case of a banking or tax review. All three matter, but the third one is usually discovered too late.

Starting point: separate finances

Before touching any software, the first rule is to absolutely separate personal money from LLC money. That means no personal purchases on the Mercury or Wallester card, no LLC invoices paid from your personal account, and every withdrawal marked as an "owner draw" from the LLC account to your personal account.

If this line gets crossed often, bookkeeping becomes impossible and, worse, the legal shield of the LLC is broken. It is the first norm and admits no exceptions.

What tools you need

For a small or medium non-resident LLC, this stack covers everything:

Mercury as the main operating account and, if you want to separate treasury, a second sub-account or Slash for reserves.
Wise Business for currencies other than US dollars, especially euros.
Wallester or Mercury virtual cards for day to day spend.
A spreadsheet in Google Sheets, Numbers or Excel; or, if you prefer software, Wave (free) or QuickBooks Online on its lighter plan.

You do not need to pay for QuickBooks Plus if your LLC bills under six figures and operates in a single dominant currency. A well-structured spreadsheet covers the use case.

Minimum structure of a clean bookkeeping

The sheet should have at least four tabs or sections:

Income: date, client, description, original currency, amount, LLC currency (USD), exchange rate applied, supporting invoice.
Expenses: date, vendor, category (software, travel, professional services, marketing, etc.), currency, amount, supporting receipt.
Inter-account movements: transfers between Mercury, Wise, Wallester and personal accounts (owner draws). They are not income or expense, but they must be traceable.
Monthly close: opening balance, income, expenses, draws, closing balance, reconciliation against the bank statement.

Monthly bank reconciliation is the step most people skip and the one that prevents 90% of problems. If your sheet says you have USD 12,450 and Mercury says USD 12,380, there are USD 70 unexplained. Finding that gap today takes five minutes; finding it next April takes two evenings.

Expense categories worth keeping from day one

Stable categories help with the close and, above all, with your filing. The most useful for service and digital LLCs:

Software and SaaS subscriptions.
Payment gateway fees (Stripe, PayPal, Adyen, DoDo).
Banking and FX fees.
Marketing and advertising.
Professional services (accounting, lawyers, registered agent).
Business-related travel.
Equipment (computer, business phone).
Coworking and office.
Professional education.
Owner draw (kept separate from the rest).

For more detail on what is deductible and what is not, see our guide on deductible LLC expenses.

Monthly close step by step

The monthly close takes 30 to 90 minutes depending on volume. The ideal routine:

Download the month's statements from Mercury, Wise and any other account.
Dump movements into your sheet, marking income, expenses and internal movements.
Attach the supporting document for each movement in a folder for that month (Google Drive with sub-folders by month works well).
Reconcile: the closing balance on your sheet must match, to the cent, the closing balance on the statement.
Save a PDF of the closed month. That folder is your backup if Mercury, the IRS or your home tax authority ever asks for information.

Currencies: the detail that creates most errors

If you bill in euros and run the LLC in USD, every time you receive a payment you must record two things: the original amount and the converted amount in USD at the day's exchange rate. The IRS accepts the daily rate or a reasonable annual average; the important thing is to be consistent and document the source (Wise, Mercury or the central bank rate).

Do not mix currencies in the same column. If "USD Amount" is your main column, convert at the moment of recording; do not leave it for later.

Year-end close and handover to the accountant

On December 31 you do an extended close: in addition to the monthly close, you generate an annual summary with category totals, gross income, gross expenses, net profit and total owner draws. That summary is what you hand to your accountant to prepare the pro forma Form 1120 and the mandatory Form 5472 for non-resident LLCs.

At Exentax we ask our clients for this package before the end of February: full-year statements, sheet with reconciled monthly closes, supporting receipts folder and an annual summary by category. With this we can prepare the return without bothering you for weeks.

Common mistakes to avoid

Mixing personal and LLC expenses. The most common and the most expensive: it breaks the shield and forces you to retrace every movement.
Not reconciling monthly. Stacking reconciliations turns a one-hour task into a multi-day job.
Forgetting FX fees. When Wise converts EUR 1,000 to USD, there is a small fee that is also a deductible expense. Not recording it means losing money.
Not keeping issued invoices. Any bank or gateway can ask you for the origin of a large inbound payment. Without the original invoice, explanations become uphill work.
Waiting until March to start. A guaranteed recipe for late filings or rough numbers handed to the accountant.

How we do it at Exentax

For clients who prefer to delegate, at Exentax we offer managed monthly bookkeeping: we pull statements from Mercury and Wise via a secure connection, categorize movements, reconcile balances and deliver a clear monthly report. You only need to keep finances separate and forward us invoices for expenses not visible in the statement (subscriptions, paper receipts, etc.).

It is the calmest way to operate an LLC: when next April arrives, the return is half done because the bookkeeping is closed month by month.

Typical scenarios where it applies

Case 1: freelancer billing 60,000 USD/year to 4 European clients.

Needs weekly reconciliation routine, free software (Wave) and simple Form 5472 template. Estimated time: 30 minutes per week. No external advisory required.

Case 2: digital agency with 3 partners and 15 recurring clients.

Requires Xero or QuickBooks Online, custom categories per project, fortnightly reconciliation and external bookkeeper from the start. Monthly cost: 250-400 USD between software and services.

Case 3: ecommerce with Stripe, Shopify and Asian suppliers.

Multi-currency and multi-gateway complexity demands A2X or Synder to automate imports. Ecommerce-specialized bookkeeper indispensable. High initial investment but avoids errors that cost thousands in corrections.

Frequently asked questions

Do I need accounting software if my LLC invoices little?

Yes. Even at low volume, manual spreadsheet bookkeeping increases the risk of Form 5472 errors and makes it harder to justify expenses to the IRS in an audit. Wave (free) or Xero at 15 USD/month solve the case. This is where Exentax steps in: we file the form, archive the receipt and, if the authority asks, your answer is already on the desk.

How do I categorize crypto payments?

Every crypto payment in or out must be recorded at its USD value on the operation date. Use a reliable exchange-rate source (CoinGecko, Coinbase). If the crypto is held, variations are not income until conversion.

Do I have to keep paper invoices?

No. The IRS accepts digital copies. What matters is that they are legible, complete and properly archived. A monthly folder on Google Drive or Dropbox is enough for a small LLC.

Can I deduct expenses paid with my personal card before opening the LLC bank account?

Yes. During the first months it is common. Record them as owner-reimbursable and book a single transfer from the LLC account once it is live. Keep the original invoice and the personal payment evidence.

When does it make sense to hire an external bookkeeper?

When your volume exceeds 50 monthly transactions or your activity gets complex (multiple currencies, ecommerce, subscriptions). Below that threshold, weekly internal discipline is perfectly viable.

Conclusion

LLC bookkeeping is not complicated, but it requires routine. Separate finances from day one, pick a simple tool, reconcile every month and keep your receipts. With that discipline, your LLC runs for years without surprises and the annual filing stops being a stressful event.

If you prefer not to handle it yourself, at Exentax we can run the bookkeeping of your LLC alongside the rest of the tax and operating package. At Exentax we review your case with real data: book a free consultation for 30 minutes.

Tax compliance in your country: CFC, controlled-foreign rules and income attribution

A US LLC is a fully legal, internationally recognized vehicle. But compliance does not end at incorporation: as an owner who is tax-resident elsewhere, your local tax authority still has the right to tax what the LLC earns. The key is under which regime.

By jurisdiction

Spain (LIRPF/LIS). An operative single-member disregarded LLC (real services, no significant passive income) is generally treated under income attribution (art. 87 LIRPF): the LLC's net profits are attributed to the member in the year they arise and integrated into the general IRPF base. If instead the LLC elects corporation treatment (Form 8832) and is controlled by a Spanish resident with mostly passive income, the CFC regime (art. 91 LIRPF for individuals, art. 100 LIS for companies) can apply. The choice is not optional: it depends on economic substance, not on the label.
Information returns. US bank accounts with average or year-end balance >€50,000: Form 720 (Law 5/2022 after CJEU C-788/19, 27/01/2022, penalties now under the general LGT regime). Related-party transactions and dividend repatriation: Form 232. US-custodied crypto: Form 721. This is where Exentax steps in: we file the form, archive the receipt and, if the authority asks, your answer is already on the desk.
Spain–US tax treaty. The treaty (BOE 22/12/1990, Protocol in force 27/11/2019) governs double taxation on dividends, interest and royalties. An LLC without a permanent establishment in Spain does not by itself create a PE for the member, but effective management can if all activity is run from Spanish territory.
Mexico, Colombia, Argentina and other LATAM jurisdictions. Each has its own CFC regime (Mexico: Refipres; Argentina: foreign passive income; Chile: art. 41 G LIR). Common principle: profits retained inside the LLC are deemed received by the member if the entity is treated as transparent or controlled.

Practical rule: an operative LLC with substance, properly declared in your country of residence, is legitimate tax planning. An LLC used to hide income, fake non-residence or shift passive income with no economic justification falls within art. 15 LGT (anti-abuse) or, worse, art. 16 LGT (simulation). The facts decide, not the paperwork.

At Exentax we structure the entity to fit the first scenario and document every step so your local return can be defended in case of review.

Legal and regulatory references

This article relies on rules currently in force. Main sources for verification:

United States. Treas. Reg. §301.7701-3 (entity classification / check-the-box); IRC §882 (tax on foreign income effectively connected with a US trade or business); IRC §871 (FDAP and withholding on non-residents); IRC §6038A and Treas. Reg. §1.6038A-2 (Form 5472 for 25% foreign-owned and foreign-owned disregarded entities); IRC §7701(b) (tax residency, substantial presence test); 31 U.S.C. §5336 (Corporate Transparency Act, BOI Report to FinCEN).
Spain. Law 35/2006 (LIRPF), arts. 8, 9 (residency), 87 (income attribution), 91 (CFC for individuals); Law 27/2014 (LIS), art. 100 (CFC for companies); Law 58/2003 (LGT), arts. 15 (anti-abuse) and 16 (simulation); Law 5/2022 (Form 720 penalty regime after CJEU C-788/19 of 27/01/2022); RD 1065/2007 (Forms 232 and 720); Order HFP/887/2023 (Form 721 crypto). Now is the moment to ask for help. At Exentax we open the case, file what is missing and reply to the relevant authority for you.
Spain–US treaty. BOE of 22/12/1990 (original DTT); Protocol in force since 27/11/2019 (passive income, limitation on benefits).
EU / OECD. Directive (EU) 2011/16, amended by DAC6 (cross-border arrangements), DAC7 (Directive (EU) 2021/514, digital platforms) and DAC8 (crypto-assets); Directive (EU) 2016/1164 (ATAD: CFC, exit tax, hybrid mismatches); OECD Common Reporting Standard (CRS).
International framework. OECD Model Convention, art. 5 (permanent establishment) and Commentaries; BEPS Action 5 (economic substance); FATF Recommendation 24 (beneficial ownership).

Applying any of these rules to your specific case depends on your tax residency, the LLC's activity and the documentation you keep. This content is informational and does not replace personalized professional advice.

A balanced banking stack: Mercury, Relay, Slash and Wise

There is no perfect account for an LLC. There is the right stack, where each tool plays a role:

Mercury (operated as a fintech with partner banks (Choice Financial Group and Evolve Bank & Trust primarily; Column N.A. on legacy accounts), FDIC via sweep network up to the current limit). Main operating account for non-residents with strong UX, ACH and wires. Still one of the most proven options to open from outside the US.
Relay (backed by Thread Bank, FDIC). Excellent backup account and for envelope-style budgeting: up to 20 sub-accounts and 50 debit cards, deep QuickBooks and Xero integration. If Mercury blocks or asks for KYC review, Relay keeps your operations running.
Slash (backed by Column N.A. (federally chartered, FDIC)). Banking built for online operators: instant virtual cards by vendor, granular spend controls, cashback on digital advertising. The natural complement when you manage Meta Ads, Google Ads or SaaS subscriptions.
Wise Business (multi-currency EMI, not a bank). To collect and pay in EUR, GBP, USD and other currencies with local bank details and mid-market FX. Does not replace a real US account but is unbeatable for international treasury.
Wallester / Revolut Business. Wallester provides corporate cards on a dedicated BIN for high volume. Revolut Business works as a European complement, not as the LLC's main account.

How to read LLC bookkeeping as a stable monthly procedure rather than as a year-end emergency

LLC bookkeeping reads more usefully when it's treated as a stable monthly procedure — bank movements imported, invoices issued and received attached, expenses classified, balance reconciled — than as a year-end emergency. The procedure doesn't change month to month, only the volume moves, and a short dated note at the close of each period in the LLC folder makes the next conversation with an accountant or a bank far more efficient.

Before going further, put numbers on your case: the Exentax calculator compares, in under 2 minutes, your current tax bill with what you would carry running a US LLC properly declared in your country of residence.

> Free consultation, no strings attached

The realistic recommendation: Mercury + Relay as backup + Slash for ad operations + Wise for FX treasury. This setup minimizes block risk and reduces real cost. At Exentax we open and configure this stack as part of incorporation.

Banking and tax facts worth clarifying

Fintech and CRS information evolves; here is the current state:

Notes by provider

Mercury operates with several federally chartered partner banks and FDIC coverage via sweep network: mainly Choice Financial Group and Evolve Bank & Trust, with Column N.A. still in some legacy accounts. Mercury is not itself a bank; it is a fintech platform backed by those partner banks. If Mercury closes an account, the balance is typically returned by paper check mailed to the account holder's registered address, which can be a serious operational problem for non-residents; keep a secondary account (Relay, Wise Business, etc.) as contingency.
Wise ships two clearly different products: Wise Personal and Wise Business. For an LLC you must open Wise Business, not the personal account. Important CRS nuance: a Wise Business held by a US LLC sits outside CRS because the account holder is a US entity and the US is not a CRS participant; the USD side operates via Wise US Inc. (FATCA perimeter, not CRS). In contrast, a Wise Personal opened by an individual tax-resident in Spain or another CRS jurisdiction does trigger CRS reporting via Wise Europe SA (Belgium) on that individual. Opening Wise for your LLC does not bring you into CRS through the LLC; a separate Wise Personal in your own name as a CRS-resident individual does report.
Wallester (Estonia) is a European financial entity with an EMI/issuing-bank licence. Its European IBAN accounts are within the Common Reporting Standard (CRS) and therefore trigger automatic reporting to the tax administration of the holder's country of residence.
Payoneer operates through European entities (Payoneer Europe Ltd, Ireland) that are also in scope for CRS for clients resident in participating jurisdictions.
Revolut Business: when paired with a US LLC, it operates under Revolut Technologies Inc. with Lead Bank as its US banking partner. The account delivered is a US account (routing + account number); no European IBAN is issued to a US LLC. The European IBANs (Lithuanian, Belgian) belong to Revolut Bank UAB and are issued to European clients of the group. If you are offered a European IBAN tied to your LLC, confirm exactly which legal entity holds that account and which regime it reports under.
Zero tax: no LLC structure delivers "zero tax" if you live in a country with CFC/tax transparency or income attribution rules. What you achieve is no double taxation and correct reporting at residence, not elimination.

How to read bookkeeping as a stable monthly rhythm rather than as a year-end rush

Bookkeeping for an LLC reads more calmly when it's treated as a stable monthly rhythm rather than as a year-end rush. Tied to a fixed slot at the start of each month, it captures the previous month's operations while they're still fresh, and removes the year-end task of reconstructing twelve months of movements at once.

The minimum viable bookkeeping system for an operating LLC

US LLC bookkeeping does not require a team: it requires discipline, the right tool and strict separation between operations. At Exentax we use a three-layer scheme that scales from month one to six-figure revenue without redoing anything.

Layer 1 - Single operating account. Every LLC inflow and outflow runs through Mercury, Relay or Wise Business. Zero personal cards on the LLC account and zero personal withdrawals without a bookkeeping entry. This single rule prevents 80 % of later audit issues. Relax: at Exentax this is what we do every week, we close it before the letter ever lands in your inbox.
Layer 2 - Connected accounting software. Wave, QuickBooks Online or Xero, wired via bank feed to the LLC account. Auto-reconciliation leaves under 5 % of transactions needing manual review when the feed works. Pre-configured category templates based on your activity so closing the month takes minutes, not hours.
Layer 3 - Supporting documentation. Digital folder organised by month with the issued invoice, the payment receipt and the bank reconciliation. When an extended KYC or a review hits, this is what you hand over; without this layer the bookkeeping does not survive a second look.
Year-end close and 5472. At December 31, ledger export and final reconciliation against bank statements. Form 5472 + 1120 pro forma feeds directly from the ledger; clean books save 4 to 12 hours of work in April.

What we are asked the most

Do I need a US accountant to keep the books? No: operational bookkeeping is handled by the owner with standard software. You do need an advisor (US or international with non-resident SMLLC experience) for year-end, 5472 and residency reporting. We split it that way so cost stays proportional to size.

What if I have two years of unstructured bookkeeping? Reconstruction from bank statements, issued invoices and gateway movements. It is hard work but feasible; we have done it with clients arriving with four mixed years. Get it ordered before the next filing, do not wait for a letter.

At Exentax we leave the operational bookkeeping documented step by step and, if you prefer, we run it for you inside the annual retainer.

Legal & procedural facts

FinCEN and IRS reporting requirements moved recently; the current state is:

BOI / Corporate Transparency Act: your LLC is NOT required to file (a competitive advantage). After FinCEN's March 2025 interim final rule, the BOI Report obligation was narrowed to "foreign reporting companies" (entities formed OUTSIDE the US and registered to do business in a state). A US-formed LLC owned by a non-resident does NOT file the BOI Report: one fewer filing on your calendar, less paperwork, and a cleaner structure than ever. If your LLC was formed before March 2025 and you already filed BOI, keep the acknowledgement. The regulatory status can change again: we monitor FinCEN.gov on every filing and, if the obligation comes back, we handle it at no extra cost. Current status verifiable at fincen.gov/boi.
Form 5472 + pro-forma 1120. For a Single-Member LLC owned by a non-resident, the final regulations of Treas. Reg. §1.6038A-1 (in force since 2017) treat the LLC as a corporation for 5472 purposes. Procedure: pro-forma Form 1120 (header only: name, address, EIN, tax year) with Form 5472 attached. It is filed by certified mail or fax to the IRS Service Center in Ogden, Utah, not e-filed via standard MeF. Due date: April 15; extension via Form 7004 to October 15. Penalty: $25,000 per form per year, plus $25,000 per additional 30 days of non-filing after IRS notice.
Substantive Form 1120. Only applies if the LLC has filed a check-the-box election to C-Corp (Form 8832): it then pays 21 % federal corporate tax and files a substantive 1120. A standard disregarded LLC does not file a substantive 1120 and does not pay federal corporate tax.
EIN and notice. Without an EIN you cannot file 5472 or BOI. The IRS does not warn before imposing penalties; you find out when an EIN is flagged or a later filing is rejected.

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For state-specific details, see our Wyoming LLC service page with closed costs and timelines.

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