Amendment of Solicitation / Modification of Contract
The SF 30 is the government's standard form for amending solicitations before award and modifying contracts after award. Master this form and you'll handle 90% of your post-award administrative work.
1Introduction
The SF 30 serves a dual purpose: it amends solicitations before award (pre-award amendments) and modifies contracts after award (post-award modifications). Every contract change you make in your career will flow through this form. Understanding what goes in each block is fundamental.
2The Form at a Glance
The SF 30 is logically divided into three major sections:
- Top half (Blocks 1 - 12): Administrative header information. Identifies the contract, the parties, and administrative details like contracting office and dates.
- Block 13: The heart of the form. Authority for the modification. This block determines whether the change is unilateral or bilateral.
- Block 14: Description of what's being changed. The actual substance of your modification.
- Blocks 15 - 16: Signature blocks. Who must sign for the change to be valid.
3Block-by-Block Overview
Administrative Blocks (1 - 12):
Contract ID Code
The contract type identifier from the underlying award document. Often blank at base level. The header row also carries Page of Pages.
Amendment/Modification No.
e.g., 0001 for solicitation amendments, P00001 for contracting-office modifications. Follow the sequence already established on the document.
Effective Date
When does this change take effect? Usually the date the CO signs, but can be different if agreed by the parties.
Requisition/Purchase Req. No.
The PR or requisition number funding this action. Not always required.
Project No. (If applicable)
If the action is tied to a specific project or program, the project number goes here. Often blank.
Issued By
The contracting office issuing the modification - your office code and address.
Administered By (If other than Item 6)
The office administering the contract. Often the same as Block 6; for DCMA-administered contracts, this is DCMA.
Name and Address of Contractor
Legal name and mailing address, exactly as awarded. The CODE and FACILITY CODE fields alongside carry the CAGE code; the contractor's UEI lives in SAM.
Solicitation Amendment (Pre-Award)
Only fill these when amending a solicitation before award. 9A is the solicitation number, 9B is the date of the original solicitation, and Item 11 is where offerors acknowledge receipt of the amendment.
Contract Modification (Post-Award)
Only fill these when modifying a contract after award. 10A is the contract/order number, 10B is the date of the original award, and Item 12 carries accounting and appropriation data when funding changes.
Block 13 - The Authority (CRITICAL): This is where you justify why you have the right to make this change. Block 13 applies only to contract modifications (never solicitation amendments), and the real form gives you four checkboxes plus a signature-requirement line:
- 13A - Change Order: Check when issuing a unilateral change order, and cite the authority (e.g., the Changes clause, FAR 52.243-1).
- 13B - Administrative Changes: Check for unilateral administrative changes (paying office, appropriation data, typos) made pursuant to FAR 43.103(b)(1).
- 13C - Supplemental Agreement: Check for bilateral modifications, and cite the authority. Both parties sign.
- 13D - Other: Check for unilateral modifications made under a contract clause other than a change order - option exercises (FAR 52.217-9), incremental funding (52.232-22), stop-work orders (52.242-15), terminations (52.249-x). Specify the type and the authority.
- 13E - Contractor signature: Mark whether the contractor is or is not required to sign this document, and how many copies to return.
Block 14 - Description of Amendment/Modification: This is the meat of your SF 30. Write what's changing. Include:
- A clear statement of what you're doing (exercising option, changing funding, etc.)
- For pricing changes: show old amount, change, and new amount
- For scope changes: describe what's being added/removed
- The standard boilerplate: "Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect."
Blocks 15 - 16 - Signatures:
- Block 15 (Contractor): Blank for unilateral mods. Both parties sign for bilateral.
- Block 16 (Contracting Officer): Always must be signed by the CO (or their authorized representative).
4Numbering Conventions
SF 30 numbering follows a pattern (though agencies can vary):
| Mod Type | Numbering Pattern | Example |
|---|---|---|
| Modification issued by the procuring contracting office | P##### (P-number, zero-padded) | P00001, P00002, P00003 |
| Modification issued by the contract administration office (e.g., DCMA) | A##### (per DFARS PGI 204.7004) | A00001, A00002 |
| Solicitation Amendment | Varies, often just sequential | 0001, 0002 or 001, 002 |
5Common Mistakes to Avoid
- ✕ Vague authority in Block 13: "Mutual agreement" alone is weak even on a 13C supplemental agreement. If a clause or statute supports the change, cite it specifically (e.g., "FAR 52.243-1(a)").
- ✕ Mixing solicitation and contract blocks: Don't fill both the 9A/9B solicitation blocks and the 10A/10B contract blocks. Pick one. If amending a solicitation, use 9A/9B. If modifying a contract, use 10A/10B.
- ✕ Missing boilerplate language: Always include "Except as provided herein..." in Block 14. It saves you later when the contractor claims a side agreement.
- ✕ Signing without authority: Only the CO (or their authorized representative per a delegation) can sign Block 16. Not the PM, not the contract specialist, not anyone else.
- ✕ Wrong modification number: Use sequential numbers. P00001 followed by P00002, not P00001 then P00003.
- ✕ Forgetting to route to contractor: A signed SF 30 doesn't mean anything until the contractor receives it (and signs it if bilateral). Route immediately upon execution.
Choose a modification type below and the SF 30 will update to show you exactly what a completed form looks like for that scenario. Click any highlighted block for more detail.