Clients, contacts, projects, expenses, time entries and invoices come over in one run, with a preview before anything is written and one button to remove it all afterwards. You can test it against your own books without committing to anything.
It is the thought of moving years of clients, projects and invoices, and the suspicion that you will find out what did not come across in about three weeks, on an invoice, in front of a client. So the renewal gets paid again. The honest fix is not a promise that nothing will go wrong. It is a preview before anything is written, and a way back afterwards.
Connect with a read token
Paste a Harvest personal access token and your account id. Billbooks reads from Harvest and never writes anything back to it.
See a preview first
A count per record type before anything is created, including how many are already imported if you have run it before.
It runs in the background
Close the tab if you like. A large account imports in stages and resumes where it stopped, so nothing times out halfway.
Undo it with one button
If it does not look right, one button removes exactly what the import created, in reverse order, and tells you what it kept.
It removes what the import created, resolved through its own record of what it made, rather than deleting anything that merely looks similar. Anything you have since built on is kept, not deleted: a client who has gained a document or a contact of their own, or a project something else now points at, stays, and the undo reports it instead of quietly removing it.
It is offered only while the import is untouched. Once you have started relying on the data, by creating your own invoice or editing an imported one, the button goes for good rather than becoming a risk.
Those two clients gained a document of their own after the import, so they stay and are listed.
Better here than in three weeks on an invoice. Three limits, stated plainly.
Clients, contacts, projects, expenses, time entries and invoices. Invoice numbers are preserved, the totals are taken from Harvest rather than recalculated, tax is carried per line, and payments are recorded for invoices that were paid or partly paid.
No. It keeps a record of what it has already imported and a second run brings across only what is new since the last one, so you can start early and catch up later.
Yes, with one button, while the import is untouched. It removes what the import created and keeps anything you have since built on, reporting what it kept. Once you start relying on the data, by making your own invoice or editing an imported one, the undo is withdrawn rather than left as a risk.
They are skipped and listed for you. We will not bring an invoice in at a guessed exchange rate, because every report built on it would then be wrong in a way nobody would notice. Billbooks does support multi-currency invoicing for the work you do from here.
No. The connection reads only, and nothing is written back or deleted there. Keep the account on its lowest tier until the year is filed so the history stays available.
It runs in the background rather than in your browser, so you can close the tab. A large account imports in stages and resumes where it left off, which is what stops a big import timing out partway.
You need permission in Billbooks for each kind of record being imported, so somebody who cannot create invoices cannot import them. Only one import can run at a time for an organisation.
Yes, 30 days with no credit card, which is the point of the preview and the undo: you can run this against your own books and reverse it before deciding anything.
An app so good you will want to get tasks done instead of putting them off. Stay on track and keep your cashflow going.
A little kit of calculators and generators, on the house.
30-day free trial. No credit card required.
Try it FreeWeighing it up first: the Harvest alternative page and Billbooks vs Harvest side by side. Work out the numbers with the invoicing software cost calculator, or read what changed in the 2026 Harvest price change.