How do I post and pay supplier invoices automatically?

1. Receipt as a purchase invoice; for OCR and Mail2Invoice in the status “Invoice received”.
2. Review: you set “Invoice checked”.
3. “Create open item”: this creates the posting draft.
4. Payment run and payment.
5. Post the payment in the bank, lock and export documents and payments.

You'll find the overview on the page Accounting for SaaS, apps and subscription business, and the opposite direction (outgoing invoices) on the page How do I automate dunning for subscription invoices with a payment term?

Fictional example: an app company receives 60 supplier invoices per month: 15 as e-invoices, 30 as PDF by email, 5 on paper, 10 as credit card receipts from SaaS tools.

According to the weclapp pricing page (as of October 2026), OCR, e-invoice capture, payment run, account assignment rules and DATEV and BMD export are included in all packages. There are three ways. First, you upload files under Purchasing > Invoices/Credit notes via the “E-invoice / OCR” button. Second, you import an e-invoice in the workflow of a purchase order after activating “Import e-invoice for purchase orders”. Third, Mail2Invoice reads a mailbox folder; it is included in all three packages, from ERP Starter. For integrations, the REST API also accepts e-invoices as XML; the invoice is created in the status “Invoice received”. Tested in a test tenant on 12.10.2026: an XRechnung (CII) was created, an incomplete file was not.

weclapp validates e-invoices on import only for technically valid format. weclapp does not process an invalid one; you can download the validation log and raise it with the issuers.

A PDF by email has been an other invoice in Germany since 2025. For transactions carried out until the end of 2026, issuers may continue to use it with your consent, and for issuers with prior-year revenue of no more than €800,000 until the end of 2027 (§ 27 para. 38 UStG, BMF FAQ question 11); paper is permitted within the same deadlines. Up to €250 total, an invoice may permanently arrive as an other invoice (including PDF), except in the case of reverse charge (§ 33 UStDV). What matters is the time of the transaction, not the invoice date. In Austria, a PDF with the recipient's consent counts as an electronic invoice as long as authenticity of origin, integrity of content and legibility are ensured (§ 11 para. 2 UStG 1994, ris.bka.gv.at). More on issuing: E-invoicing for subscription providers. This does not replace tax advice.

The weclapp docs describe Mail2Invoice (as of 20.05.2026); release 26.04.1. It is included in all three packages, from ERP Starter. It reads the emails of the last 30 days (PDF and XML attachments) roughly every five minutes. As the source, you choose a subfolder, not the inbox. The target folders “Error” and “No processing” are optional; if you set them up, you check them regularly, because those invoices are not yet captured. The docs do not mention duplicate invoices. Tested in a test tenant on 12.10.2026: for e-invoice import via the REST API, weclapp flagged a second invoice with the same number from the same supplier as a duplicate (“DUP-” before the internal number, even with a different amount), but still created it; you decide whether it is a duplicate. For a document created manually or via API, there was no warning. Whether Mail2Invoice detects duplicates, we have not tested.

With OCR, weclapp assigns the supplier via customer number, company name or VAT ID and reads invoice number, date, line items and amounts. According to the docs (as of 24.09.2026), the following currently applies: purchase invoices only, no credit notes or cancellation invoices; scans at 300 dpi as PDF, JPG, PNG, GIF or TIF; payment term and payment method cannot be read out in principle. How well recognition works for your suppliers only your documents will show. On the document, the API carries the flag createdViaOcr (read-only); we have not seen an OCR document. The document carries no indication of Mail2Invoice or the original email.

OCR is performed by an external service provider; which one, weclapp states differently. An administrator must consent. Invoices also contain names and contact details of individuals: coordinate the consent with your data protection officer. You clarify the service provider and the contractual basis with weclapp before consenting.

weclapp looks for the account in this order: posting account on the item, account assignment rule in the account mapping (for example by payment method or flag), tax account mapping, default account. For OCR invoices, the line items are initially created manually; weclapp only sets an item including posting account if it can unambiguously match the item number (docs, as of 15.07.2024). Without an item, the rule, tax account or default account applies. The default setting of the accounting assistant is usually enough; which rules of your own you need, you clarify with your tax advisor.

The supplier master record is important: weclapp takes payment term, payment method, cost center, cost type and payment block from it.

This does not replace tax advice.

You can only deduct the German VAT shown on an invoice if you hold an invoice issued in accordance with §§ 14, 14a UStG (§ 15 para. 1 sentence 1 no. 1 UStG). All mandatory information under § 14 para. 4 UStG must be on the document, such as name and address of both parties, tax number or VAT ID, date, invoice number, type and scope of the service, time of the service as well as consideration, tax rate and tax amount. According to weclapp, e-invoice validation only checks the format; whether the information is correct, only you can see. For invoices up to €250 total, less information is sufficient (§ 33 UStDV, not for reverse charge).

Invoices from software companies abroad are often not a German e-invoice; depending on the seat, the recipient of the service owes the VAT (reverse charge, § 13b UStG), and a separate provision applies to this self-assessed tax (§ 15 para. 1 sentence 1 no. 4 UStG). How you post this, you determine with your tax advisor.

This does not replace tax advice.

Under Finance > Payment run, weclapp suggests due open items that you pay online. According to the docs (as of 2023), an invoice without a payment term is treated as due immediately. If it is missing in the supplier master record or the invoice differs, you correct it on the document before the payment run.

According to the docs (as of 2024), payments can only be executed online via Tink and finAPI; only finAPI offers a bulk transfer, and your bank must support it. For Tink, retrieval applies only to banks with PSD2 interfaces; ask weclapp support in advance. Without a connection, you download the payments as a SEPA or SWIFT file.

For card receipts (10 in the example), there is no bank transfer. Either you mark the open item as paid in the open items list; no payment is linked to it in the process. Or you create the card charge as a manual payment on the open item (dollar sign); it is then cleared but not yet posted. How you post card statements, you clarify with your tax advisor. This does not replace tax advice.

Invoice and payment are posted separately. If you take the purchase invoice through the workflow to the open item, weclapp creates a posting draft in the journal. The bank movement comes into weclapp via the payment service provider or via bank statement import; without either, you create the payment manually on the open item. You post it in the bank via quick posting or detail view; it too is initially a draft. Check the postings before locking, because afterwards they can only be corrected via reversal posting. For your tax advisor, you lock documents and payments and export them: in Germany via DATEV export (DATEV handover from weclapp), in Austria via BMD export (Accounting for SaaS in Austria).

This does not replace tax advice.

Your tax advisor can get free access to your weclapp system on request, in every package, including ERP Starter.

Legally, for Germany: for VAT purposes you retain incoming invoices for eight years (§ 14b para. 1 UStG), including PDF, paper and card receipts; books and annual financial statements for ten years (§ 147 para. 3 AO). The period does not expire as long as the assessment period for the taxes concerned has not yet expired. For an e-invoice, you retain at least the structured data (for example the XML file) unchanged. For e-invoices, archiving outside a GoBD-compliant system is, according to the BMF, generally not a breach for VAT purposes; the GoBD for your bookkeeping you clarify with your tax advisor.

In weclapp, the uploaded e-invoice is on the document in the “Documents” tab; from the open item onward, according to the docs (as of December 2024), it is stored permanently and can no longer be deleted. Tested in a test tenant on 12.10.2026: weclapp itself stores the XML of an imported e-invoice as a document, and via API a PDF can also be attached; both could be retrieved unchanged. Individual documents could not be deleted, not even before the open item. For OCR, paper, card and Mail2Invoice documents, the docs do not describe where the original file is stored; we have not tested that. Whether a scan may replace the paper original, you clarify beforehand with your tax advisor. Different rules apply to Austria, at least seven years of retention (§ 132 BAO): E-invoicing in Austria.

This does not replace tax advice.