If you invoice the same clients every month, most of each invoice never changes — the client's name, billing address, and terms are the same, only the line items and dates move. Retyping the static parts for every client, every cycle, is pure busywork. It can be automated.
To auto-fill invoices for multiple clients, save each client's billing details as a reusable profile, then generate an invoice per client from that profile instead of retyping. An AI form-filler like Filly AI can batch-fill the same invoice across many client profiles at once, then export the finished files or share them for payment. The free plan covers up to 10 documents a month, no card.
Manual invoicing vs auto-fill, side by side
| Task | Manual, per client | With Filly |
|---|---|---|
| Enter recurring billing details | Retyped on every invoice | Saved once per client, reused automatically |
| Produce a monthly run for 20 clients | 20 documents, one at a time | One batch fill |
| Keep a client's address consistent | Re-checked each time | Verified once on the profile |
| Catch an uncertain field | Easy to miss in look-alike docs | Color-coded by confidence for a quick check |
How do you set up reusable invoice details?
Save each client once — name, company, billing address, email, and any standing terms. Start from the invoice template or upload your own invoice as a PDF or Word file. From then on, picking a client fills the recurring fields automatically.
Can you generate many invoices at once?
Yes. Batch fill applies one invoice to several client profiles in a single pass, so a monthly billing run becomes one action instead of one document at a time. You review the set, then export or send.
How do you avoid billing errors across clients?
Because each invoice is filled from a single saved profile, a client's details are consistent everywhere and you verify them once. Fields are color-coded by confidence, so anything uncertain surfaces for a quick check rather than hiding in a stack of look-alike documents.
Does this work for freelancers and agencies?
It's built for exactly that — anyone sending repeat paperwork to a roster of clients. The same reusable-profile idea fills contracts and intake forms too; see filling contracts online free and filling any PDF form online free.
Frequently asked questions
Can I auto-fill invoices for free?
Yes. Filly's free plan includes up to 10 filled documents a month with no credit card. Batch fill and higher limits start at $19/month.
How many invoices can I batch at once?
Paid plans batch-fill up to 5 (Solo) or 20 (Pro and above) client profiles per run.
Can I use my own invoice design?
Yes. Upload your existing invoice as a PDF or Word file — Filly reads its fields and fills them from the client profile.
Is my clients' billing data kept private?
Filly encrypts stored data, publishes its sub-processors, doesn't train AI on your files, and supports deletion — see the security page.