Billing Questions:
Contact: Stacy Walker
Phone: 1-530-752-8100 (AR is handled remotely, communication by email is preferred, or call and leave a voicemail)

Billing Process Overview:

  1. Review sample preparation requirements prior to placing your order. Place your order by emailing the completed Analysis Order Form and Sample List to If your administration requires a Purchase Order, request a quote at this time.
  2. The SIF will email a confirmation upon receipt of samples. After the sample analysis is complete, and during data processing, please expect an invoice by email from
  3. Data will be released upon receipt of proof of payment, which may include a validated purchase order, EFT transaction receipt, or credit card payment receipt.

The SIF's revised invoice process requires payment for services rendered before data files are delivered. This change was initiated to reduce overhead costs associated with SIF accounting services.

We are working to ensure minimal impact to turnaround times, and this change will not affect how sample charges are calculated or our ability to address any client concerns.  We thank you for your assistance through this transition and, as always, we appreciate your business.


Analysis Order Forms (AOF) are required by the SIF, not only to identify your shipment of samples, but to provide important billing information to set-up an account with our lab. The data will be reported to the Researcher and PI addresses you provide on the AOF. A billing account will be set-up using the information you provide in the Billing Section. The Billing Contact should be the person or department paying the invoice, as the invoice will be emailed to their attention.

Purchase orders (PO) may be required by your university / institution in order to 1) establish the terms of the services you are requesting from the SIF and 2) to authorize and allocate funds to pay for services rendered by the SIF. Contact your accounting department to determine if a purchase order is necessary. Purchase orders should be emailed to (cc:

Estimates / Quotes  help clients establish a budget, purchase order, and allocate funds with their funding agency. Estimates/quotes are not invoices. We do not issue Proforma Invoices for prepayment. The prices listed on each of our Analytical Services pages can be used for quick budgeting, but are subject to change, and incidental fees may be incurred at time of analysis.

Invoices are typically generated after samples have been analyzed, prior to data reporting. Invoices are e-mailed as pdf attachments from

Clients can request to be invoiced ahead of their sample analysis, however, in the event of poor/lost data, refunds may be difficult to process. Instead, we prefer to rerun the samples or apply the credit towards future sample analysis.

Invoices are payable upon receipt. You may receive a past due notice if payment is not received within 60 days of invoice delivery. Delinquent accounts over 241 days old shall have a HOLD placed on the account, suspending further sample analysis until the balance is paid.

Payment by check: (i.e. personal check, cashier's check, money order) Please include your customer number and invoice number on your check. Payments missing this information may be returned minus a fee.

Make checks payable to: The Regents of the U.C.

Mail payment to: UC Davis AR Lockbox, P.O. Box 741816, Los Angeles, CA 90074-1816

Payment by bank wire transfer: Please e-mail to request our bank information or to inform the SIF of payment details. Multiple invoices can be combined into one wire transfer, but please remember to include the invoice number(s), otherwise payment may be returned minus a fee. EFT fees should be paid by the payer in addition to the invoice balance due.

Payment by credit card: The SIF prefers payment by credit card. Your invoice will include a link  and instructions on how to pay via our secure credit card payment website. DO NOT SEND ANY CREDIT CARD INFORMATION via e-mail, phone, fax, letter, or Analysis Order Form to the SIF. To maintain security of your personal information, SIF staff are NOT allowed to handle credit card information.

University of California Researchers: University of California researchers should pay by FAU or recharge account to receive the discounted UC rate. UC clients (not including Davis campus) will receive their bill in the form of an Intercampus Order form (IOC). The IOC must be returned to before the 20th of each month to complete the funds transfer for that month's ledger. If you have a spending deadline, please notify us 1-month in advance.

Records Retention: The SIF keeps all submitted paperwork and invoices for 3 years minimum, 6 years maximum. Do not send your only copy of any paperwork to the SIF, always retain a copy for your records. E-files of data, sample lists, and invoices are backed-up and retained indefinitely. If you lose your weight sheets or your data files, we can help you! Request Lost Data/Paperwork.