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One job can wear two invoices. What it cannot survive is two versions of what the job was.

The request is usually innocent: two departments shared your work, each holds part of the budget, and each will only pay from its own pot. So the client asks you to split the invoice. The danger is not the split itself, it is what a careless split creates: two documents that look like two jobs, two amounts nobody can add back to the agreement, and two approval trails where a short payment on one side becomes an argument about the whole job. Handled the way this page sets out, the split stays what it really is, a way of presenting one bill to two payers, while the work underneath stays one job, delivered once, accepted once, on one record both departments can check.

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Updated November 11, 2026. First published November 11, 2026. The records quoted below are real and public, read back from the live service on November 11, 2026.

Step 1. Agree the split in writing before you issue anything

Four facts decide whether this goes smoothly, and all four belong in one short written message from the client before any invoice exists. The amounts: exact figures or exact percentages for each department, adding up to the agreed job total, not to a new total invented at split time. The references each department needs: its cost code, purchase order number, or project tag, in the exact form its finance team will look for. The name and email of the person in each department who receives and approves their part. And the payment terms for each part, stated separately, because two departments in one company can run on different cycles and you want that visible now, not discovered at day 40. If the client cannot yet name the split, the job is not ready to invoice; send the single job summary with the total and ask them to return the split in writing. Guessing a split for them creates the one outcome you must avoid: invoices that match nobody's budget and get rejected by both sides.

Step 2. Issue two invoices that visibly belong to one job

Each invoice should be boringly explicit about its family. Number them as a pair, for example INV-1042-A and INV-1042-B, or keep your normal sequence and write part 1 of 2 and part 2 of 2 on both. On each one, state the full job total, the amount of this part, and the amount and destination of the other part, so anyone holding only one document can reconstruct the whole bill in ten seconds. Both invoices carry the same job reference: the same delivery date, the same short description of the work, and the same link to the job's delivery record. Neither invoice re-describes the work in its own words; the moment the two documents describe two slightly different jobs, you have handed two finance teams two different things to query. The amounts must sum exactly to the agreed price, to the cent, with any tax treated the same way on both parts. A split is arithmetic wearing a suit: every number on either page should be derivable from the agreement plus the split message, with nothing left over.

Step 3. Keep one acceptance for the whole job underneath the split

The split divides who pays. It must never divide what was decided. The work was one job, so it gets one delivery record and one acceptance covering all of it, recorded before or alongside the invoices, and both invoices point at that same record. The record format is AER-1, published as an IETF Internet-Draft (draft-zambo-aer1-26), and each step carries a verifiable receipt: a receipt proves the saved result was not changed since it was saved. The two public records below show the decision layer each of your two invoices should be pointing at:

Accepted: the decision is on the record

Pending: checked, and still waiting on a decision

Read the accepted record as the shape you want: one job, 4 steps, all checked, one client decision with a decider and a date, release state ok_to_release. Two departments can split the payment for that job any way their budgets require; neither needs its own acceptance, and neither can later claim its part covered different work. The pending record shows why the order matters: decision still open, release on hold. If a client asks for split invoices before anyone has accepted the work, the split is premature, because two departments are being asked to pay for a job whose own record still reads undecided. Get the acceptance first, then split the bill.

Step 4. Track payment per part, and treat a short part as a balance, not a new dispute

From issue day, keep a one-line ledger for the job: total, part A amount and state, part B amount and state, balance still open. When part A pays, confirm it in writing the same day, naming the part, the amount, and the balance that remains on part B, and send that confirmation to both contacts, because the paying department's team will file it and the other department now knows exactly where the job stands. If one part pays late or short, your follow-up goes to that department about that part, with the job total and the settled part shown, so the conversation stays arithmetic. What you must not do is re-issue, re-split, or quietly move an unpaid balance onto the other department's invoice: a rebalanced split needs the same written agreement the original split needed, from both sides. When the second part lands, close the job with one zero balance line sent to both contacts, listing both invoice numbers, both payment dates, and the record link.

Step 5. Set the next shared job up so the split takes five minutes

Clients who split once will split again, and the second time should cost you one message. At the start of the next job, ask the split question with the deposit question: which departments, what shares, which references, who approves each part. Put the answers in the job agreement as a billing note, so the split is a term of the work rather than a surprise at invoice time. Run the job on its single record as usual, and at delivery the invoices are a formatting step: same record link, paired numbers, amounts from the agreed note. If one department's share of the work is genuinely its own deliverable with its own acceptance, that is no longer a split invoice, it is two jobs, and it should be priced, recorded, and accepted as two jobs from the start. The line between the two shapes is the acceptance: one decision means one job with a split bill; two decisions mean two jobs.

What this page cannot settle

This page cannot make two departments coordinate with each other; if one side refuses its share, the record shows what was agreed and delivered, and the argument about who inside the client pays is theirs to settle, with your ledger as the shared facts. It is general information, not accounting or tax advice; how split invoices are booked, and how tax is apportioned between them, depends on your setup and jurisdiction. A verifiable receipt proves the saved result was not changed since it was saved. It does not prove anything about payments or internal budgets; what the work record settles is the half underneath the split, that one job was delivered and accepted once, for one agreed total.

Frequently asked questions

My client wants one invoice split across two departments. How do I handle it?

Keep the job whole and split only the bill. First get the split in writing: the exact amount or percentage for each department, the reference each one needs, such as a cost code or purchase order number, the named approver on each side, and the terms each part runs on. Then issue two invoices that visibly belong together: paired numbers or part 1 of 2 and part 2 of 2 on both, the full job total and both part amounts printed on each, the same delivery date and the same link to the one delivery record, and amounts that sum exactly to the agreed price. The work itself keeps one acceptance covering the whole job, recorded once, so neither department can later treat its part as a different job. Track the two parts on one ledger line, confirm each payment in writing to both contacts, chase a late part as a balance on that part only, and close with a single zero balance line when both have landed.

Should each department get its own acceptance or sign-off?

No, and this is the point most splits get wrong. Acceptance is a decision about the work, and the work was one job: one delivery, one record, one decision about whether it is accepted, with a decider and a date. If each department accepts separately, you have created two decision states for one delivery, and the day one side accepts and the other queries a step, the job is somehow both accepted and not. What each department does need is its own payment approval inside its own finance process: its approver releasing its part against its reference. Keep those two layers separate in your paperwork. The job record carries the single acceptance both invoices point at; each department's internal approval is their process, noted on your ledger with its date, and never a second acceptance of the work itself.

What if one department pays and the other refuses?

Then you hold a part-paid job, and the paperwork decides how clean that is. Send the paying side its confirmation and keep its money clearly applied to its part; never reassign the refused share onto the paid department without a new written agreement from both sides. The refusal itself is worked like any non-payment, but scoped: the amount is that department's part, the evidence is the same job record plus the written split that assigned the share, and the person who agreed the split for that department is the person who answers for it. Because your invoices showed the whole job on both documents, nobody can credibly claim the refused part belonged to some other arrangement. What the record cannot do is force an internal budget fight to resolve; it makes the facts one page long for whoever inside the company has to settle it.

Can I just send each department an invoice for half without mentioning the other?

You can, and it is the version of this that goes wrong. Two unconnected invoices for two halves of one job read to any finance team as two jobs, so each gets queried on its own terms, each can be rejected for missing context the other one held, and when one pays and one does not, there is no document anywhere that shows they were ever parts of one bill. The split only works because it is visible: totals, parts, and the shared record printed on both. That visibility is also your protection on price: an unconnected half invoice invites the reading that your rate for the work was the half amount, quoted back to you on the next job. Five extra lines on each invoice are the whole cost of doing it the safe way.

How do I run a shared job so the split is easy when the invoice comes?

Run the job on one record from the first step, so delivery and acceptance exist as a single checkable thing before billing is even discussed. When the work runs through Zambo, every step lands on the job record with a verifiable receipt under AER-1, published as IETF Internet-Draft draft-zambo-aer1-26, the client accepts on that record, and the acceptance view shows status, decider, date, and release state, which is the single decision both department invoices then point at. New users get 20 calls and 1 wrap-up free every day per agent, and picking up work in another AI is always free. For $0.99, run your next two-department job on one record, agree the split in writing at the start, and issue the paired invoices against the accepted record so both finance teams are paying against the same facts: get the Day Pass. A Day Pass is unlimited for 24 hours, no subscription. Ongoing use is the Zambo Pass at $29 a month, $19 a month for $ZAMBO holders, or Lifetime at $250 one time.

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