Invoice OCR

    AI Invoice Capture and OCR for Enterprise Processing

    Document invoices — PDFs, scans and images — have to become structured data before any accounts-payable process can act on them. Drelo.ai captures those documents, extracts header and line-item data, validates what was extracted, and hands a structured invoice record to your ERP, with anything uncertain routed to a person instead of posted quietly.

    Header & line extractionNo per-supplier templatesConfidence-based reviewStructured output
    Explore Invoice Automation

    Document invoice capture

    Document invoice capture is the step that turns an unstructured file into data your systems can use. It covers taking the document in, working out what kind of document it is, reading its content, and deciding which value belongs to which invoice field.

    In an enterprise, this is harder than it sounds for one reason: variety. Suppliers do not agree on layout, wording, language, where totals sit or how line items are tabulated — and they change their layouts without telling anyone. Capture has to cope with that variety rather than assume it away.

    What arrives in practice

    • ·PDFs generated from a supplier's own system, with a readable text layer
    • ·PDFs that are really images, produced by printing and scanning
    • ·Scanned paper of varying quality, sometimes stamped or annotated
    • ·Photographs of invoices taken on a phone
    • ·Multi-page invoices, and single files containing several invoices
    • ·Attachments that are not invoices at all — statements, reminders, delivery notes

    From document to structured record

    Document processing pipeline
    STEP 01
    PDF / image
    • Email or upload
    • Scan or photograph
    STEP 02
    Document capture

    Pages are separated, oriented and assessed for readability.

    STEP 03
    Field extraction
    • Invoice number
    • Supplier
    • Dates
    • Amounts and tax
    • PO reference
    • Line items
    STEP 04
    Validation

    Arithmetic, identity, completeness, duplicates and references are checked.

    STEP 05
    Structured output

    One normalised invoice record with the source document linked.

    STEP 06
    ERP / AP process
    • Clean records continue
    • Uncertain fields go to review

    Where a field cannot be read with confidence, the invoice becomes an exception instead of continuing with a guessed value.

    Source file types and what they require
    Source fileWhat has to happenEffect on review
    Digital PDFCharacters are already present; the work is structural interpretation of fields and tables.Fewer fields typically need confirmation.
    Image PDF or scanText must be recognised from pixels before fields can be assigned.Resolution, contrast, skew and stamps increase the review rate.
    PhotographRecognition plus correction for angle, lighting and cropping.Most likely to raise a low-confidence exception.
    Multi-invoice fileDocuments are separated before fields are assigned.Separation errors surface as exceptions rather than merged records.

    All source types converge on the same structured output; the difference shows up as how often review is needed.

    PDF and image invoices

    The distinction that matters most is whether a file carries a text layer. A digitally generated PDF already contains its characters, so reading it is reliable and the work is interpretation. An image-based PDF or scan carries only pixels, so recognition has to happen first and the quality of the original sets a ceiling on what follows.

    Digital PDFs

    Text is already present and readable. The challenge is structural: identifying which text is which field, and reading tables correctly across page breaks.

    Scans and images

    Text must be recognised from pixels first. Resolution, contrast, skew, stamps and marks all affect what can be read with confidence.

    Both paths converge on the same structured output, so downstream validation and ERP handoff behave identically. The difference shows up as how often review is needed.

    Data extraction

    Extraction assigns recognised content to invoice fields. It works at two levels, and the second is consistently the harder one.

    Header level

    • ·Supplier identity and address details
    • ·Invoice number and invoice date
    • ·Currency and payment terms
    • ·Purchase order or contract references where present
    • ·Tax amounts and rates
    • ·Net, tax and gross totals

    Line level

    • ·Item description and supplier article reference
    • ·Quantity and unit of measure
    • ·Unit price and line total
    • ·Line-level tax and discounts where stated
    • ·Delivery or order references carried per line

    Each extracted field carries a confidence signal. That signal is what makes the difference between a system that hides mistakes and one that surfaces them — it decides which invoices continue automatically and which stop for a human look.

    Illustrative extraction example
    Supplier invoice (example document)
    NORTHFIELD COMPONENTS BV
    Invoice INV-2024-00871 · 14 March 2024
    Order reference: PO-4500912
    3 line items · goods delivered
    Net 12,480.00 · VAT 21% 2,620.80
    Total due EUR 15,100.80
    Extracted fields
    Invoice number
    INV-2024-00871
    Supplier
    Northfield Components BV
    Invoice date
    2024-03-14
    PO reference
    PO-4500912
    Net
    12,480.00
    Tax
    2,620.80
    Total
    15,100.80
    Currency
    EUR

    Fictional example data shown to illustrate the field structure produced by capture. Each field carries a confidence signal; a value below the threshold becomes an exception rather than a posting.

    Validation

    Extraction alone is not trustworthy, whatever technology performs it. Validation is where extracted data is tested rather than believed.

    • ·Arithmetic: line values sum to the net, tax is consistent, net plus tax equals gross
    • ·Plausibility: dates, currency and tax treatment make sense together
    • ·Identity: the supplier resolves to a known record in your master data
    • ·Completeness: fields your process requires are actually present
    • ·Duplicates: the invoice has not already been processed
    • ·References: purchase order or delivery references exist and are recognised

    The combination matters more than any single check. A misread digit that survives recognition is usually caught because the totals no longer add up — which is exactly the point of validating rather than trusting.

    Structured output

    The result of capture is one structured invoice record per document: a normalised set of header and line fields, in consistent units, currencies and code values, with the source document linked to it.

    Normalisation is what makes downstream steps possible. Once every invoice — from a digital PDF, a scan or a structured EDI message — has the same internal shape, validation, matching and ERP integration can be defined once instead of per channel.

    Exception handling

    An exception means the process refused to pass on something it could not stand behind. That is the desired behaviour, not a shortfall, and it is the safeguard that allows automation to be used on financial data at all.

    • ·Confidence below the threshold on a field that matters
    • ·Source quality too poor for reliable reading
    • ·Totals that do not reconcile with the extracted lines
    • ·Supplier not recognised in master data
    • ·Missing purchase order or reference information
    • ·Suspected duplicate of an invoice already processed
    • ·A document that turns out not to be an invoice

    Each exception records what failed and on which invoice, and the invoice waits visibly until it is resolved. Review outcomes are what make the process improve over time.

    ERP handoff

    Once an invoice record is validated, it is handed to the target system through the integration path agreed for that landscape. Integration architecture depends on the target environment and implementation requirements — the options are described on the integrations page, and SAP landscapes specifically on the SAP AP automation page.

    Where an invoice references a purchase order, capture output is also what makes three-way matching possible: matching can only compare quantities and prices that were captured reliably in the first place.

    How to judge capture quality honestly

    Rather than compare published accuracy figures, measure on your own documents. A short evaluation answers the questions that actually affect your workload.

    • ·How many invoices pass end to end without any human touch
    • ·How often a field needed correcting, split between header and line level
    • ·How much of the exception volume comes from document quality versus master data gaps
    • ·How long a review takes when it is needed
    • ·How the answers differ between your best and worst suppliers

    Frequently asked questions

    What accuracy should we expect?

    We do not publish an accuracy figure, because a number measured on one document mix says little about another. Accuracy depends on source quality, layout variety, language, whether line items are needed and how strict your validation is. The honest approach is to run a sample of your own invoices and measure the result on your documents.

    Is extraction ever wrong?

    Yes. Any capture technology reading a document can misread a field, and we do not present it as perfect. That is precisely why validation and confidence-based review exist: the goal is that a misread field is caught as an exception rather than posted silently.

    What is the difference between OCR and invoice capture?

    OCR turns pixels into text. Invoice capture is the wider job: deciding which text is the invoice number, which block is the supplier, which rows are line items, then normalising and validating what was found. OCR is one step inside capture.

    Do we need a template for each supplier?

    Avoiding per-supplier templates is the intent. Template-based approaches break whenever a supplier changes layout, which is unmanageable across a long tail of vendors. Layout-independent interpretation plus validation handles variety better.

    What about poor-quality scans?

    Low-resolution scans, skewed pages, stamps over text and handwriting all reduce what can be read reliably. Where quality prevents confident capture, the invoice is raised as an exception rather than guessed at.

    Are line items extracted, or only header data?

    Both are in scope. Line-item extraction is harder than header extraction because table structures vary, so it is the area where confidence thresholds and review matter most — especially where line-level matching is required.

    Test capture on your own invoices

    Send a representative sample of your document mix — best and worst cases — and we will discuss what capture looks like on your documents rather than on a benchmark.

    Explore Invoice Automation