A mastering approval checklist is the list you run through before you say “approved” on a master. It covers four things: the handoff (right mix, right file), the listen (several systems, start to finish), the technical specs (format, loudness, true peak, metadata), and the paper trail (who approved which exact file, and when). Skip any of the four and you get the same result: a “final” that needs a fifth revision after release.
This guide is for mastering engineers, mixing engineers, producers and studio owners who send masters for review. It is also for the clients who have to approve them. Use it as written, or copy the parts you need into your own workflow.
TL;DR
- Approve one named mix before mastering starts, and send it as an uncompressed 24-bit WAV or AIF with headroom.
- Listen to the master from start to finish on at least three systems, and write every note with a timestamp.
- Check the file, not just the sound: format, sample rate, bit depth, integrated loudness, true peak, duration, fades and metadata.
- Collect all feedback into one list per round, with one person who has the final say.
- After sign-off, archive the exact delivered file with a checksum and a dated approval record.
Table of Contents
- Before mastering: lock the mix and the handoff
- Decide the targets before you listen
- The listening pass
- The technical pass: check the file, not just the sound
- Giving notes the engineer can act on
- Handling revisions and conflicting feedback
- Final approval: how to document the sign-off
- Run the whole checklist in one place
- Our perspective
- FAQ
- Sources
Before mastering: lock the mix and the handoff
Most mastering problems are decided before the mastering engineer opens the session. A master can only be as approved as the mix it came from, so the first part of the checklist belongs to whoever sends the files.
Mix checks
- The mix is balanced and clear in more than one listening environment, free of clipping, and has a healthy low end. One mastering prep guide also asks that instrument-specific problems be fixed on the individual tracks, not left for mastering to rescue.
- Peaks sit around -6 dBFS, and the mix is bounced as uncompressed WAV or AIF at 24-bit and 44.1 kHz or higher, according to the same guide.
- You have decided whether any processing stays on the stereo bus. A mastering handoff guide says to record this, and not to change the approved mix just to make the numbers look better.
- Intros, fades, edits and reverb tails have been checked. A master delivery checklist lists these alongside alternate versions such as instrumental, clean and acapella.
Handoff sheet
A short handover sheet saves several emails. A mixing and mastering handover guide suggests including:
- Project and track title, version and intended use
- A named decision maker and approval contact
- Exact filenames and what each file contains
- Reference links or characteristics
- Known problems, with timestamps
- Agreed deliverables, deadlines and revision arrangements
One approved mix per track
Pick one approved mix per track and give it a stable filename with the artist, song title, mix version and approval date or version number. Then copy it into the handoff folder and play that copy from beginning to end. This catches the opening, the final decay, edits, fades, vocal entrances, transitions and accidental silence, as the same handoff guide explains.
One naming habit worth adopting: skip the word “final” in filenames. A production checklist recommends a pattern like SongName_STAGE_BPM_Key_v#.wav for this reason. “Final” is always followed by “final_v2”.
For albums, Bobby Owsinski’s mastering checklist adds a few items. Confirm how the master will be delivered, set the desired loudness and reference song, finalize the track sequence, flag fades and cross-fades between songs, and back up the session and master before sending.
Decide the targets before you listen
You can’t approve a master against nothing. Settle these before the first review round:
- Destination. Streaming, CD, vinyl, tape, broadcast or a mix of these. Each has different format and loudness needs, and the prep guide above asks you to choose them up front.
- Loudness approach. Decide how loud the master should be and why, instead of leaving it to whoever pushes the limiter hardest.
- Reference track. Pick at least one, and confirm the mix sounds similar to it. If you share references with the mastering engineer, keep it to one to three lawful links or files that illustrate a specific trait such as vocal presence, low-end balance, width or restraint, as the IHHR guide suggests.
- Versions. List every version you need mastered: main, instrumental, clean, radio edit, and so on. Getting masters for all versions is on the Songkeeper checklist too, and it is much cheaper to ask now than after sign-off.
The listening pass
Numbers tell you the file is clean. Your ears tell you whether it is right. Run the listening pass in this order.
Listen start to finish, on familiar gear
Star Sound Studios advises listening from start to finish on familiar headphones, your usual speakers and a modest playback system, at a comfortable level. Write down specific concerns with a timestamp and a short description, and only then approve or request changes.
Don’t stop at the first section you like or the one that bothers you. Endings, transitions and the last 10 seconds are where approvals go wrong.
Check translation
A radio-ready submission checklist describes a translation check across studio monitors, headphones, mono playback and everyday speakers. You are listening for three things:
- The lead element stays intelligible.
- The low end stays controlled.
- The chorus gains energy without a painful jump in brightness or loudness.
A/B against the approved mix
Play the master against the approved mix at matched volume. The master should sound like the same song, only more finished. If the balance changed (vocal pushed back, bass heavier, cymbals harsher), that is a note. Listen for clipping and artifacts as well, as the Songkeeper checklist recommends.
The technical pass: check the file, not just the sound
A master can sound great and still be unusable because of a wrong sample rate or a clipped true peak. This is the part of the checklist most often skipped by reviewers who are not engineers, so the engineer should supply the numbers and the reviewer should confirm them.
| Check | What to confirm | Why it matters |
|---|---|---|
| File format | WAV or AIF, uncompressed | No lossy artifacts in the master |
| Sample rate and bit depth | Matches the brief, e.g. 24-bit for archive, 16-bit/44.1 kHz for distribution | Songkeeper lists these delivery formats |
| Channel configuration and duration | Stereo or as briefed; length matches the approved mix | Catches truncated or padded bounces |
| Integrated loudness | Within the destination’s target tolerance | Forte’s deliverables checklist says to measure it on the final master |
| True peak | Under the destination’s ceiling, read on an oversampled true-peak meter | Sample-peak meters can miss peaks, per the same checklist |
| Stem sum (post and broadcast work) | DX+MX+FX sum matches the master within numerical noise | Confirms stems and master belong together |
| Fades, edits, silence | Clean start and end, no accidental gaps | Found only by playing the whole file |
| Metadata | Titles, artist, songwriter, producer, ISRC, release date | Listed on the ASP delivery checklist |
For CD masters, add the PQ sheet: client or label, artist, album and song titles, ISRC codes, CD Text, start and stop index times, and control notes, reflecting the approved content, as this mastering workflow chapter describes.
If you need stems, a tempo map or MIDI delivered with the master, spell out what that means in the acceptance criteria. A revision-round guide recommends specifying things like aligned start point, sample rate and bit depth, instead of leaving them ambiguous. Our own stem delivery policy guide goes deeper on that.
Check at more than one stage
QC at the end is the most expensive QC. One article on documentation for audio projects suggests checking in stages: a rough-edit check catches bad edits, a pre-mix check catches missing or mislabeled tracks, and a pre-delivery check confirms the exported files match the approved version and the client brief.
Giving notes the engineer can act on
Vague notes cost revisions. “Make it punchier” can mean six different moves. Anchor every note to a place in the audio.
A good note has:
- A timestamp or section (“1:42, chorus 2”)
- What you hear, in plain language (“the lead feels sharp”)
- A priority (must fix, nice to have)
- A reference only when it clarifies a trait
The IHHR guide frames notes as observations and priorities, for example saying a lead feels sharp at a given time, and describing translation issues and how sections relate. The handover guide above makes the same point from another angle: anchoring feedback to where the problem occurs means it can be tested inside the session.
Our timestamped feedback process guide walks through this in more detail.
Separate corrections from new requests
There are two kinds of notes. A correction fixes something that does not match the brief or the approved mix: a click, a cut-off tail, a level jump. A new creative request changes the brief. Group notes by track and timestamp and keep the two types apart, as the handover guide recommends. This is the line between a free fix and a billable revision, and it is easiest to draw before the work starts.
Handling revisions and conflicting feedback
When three people send three different opinions by text, you do not have a revision brief. You have a negotiation.
- Name one decision path. The IHHR guide suggests naming the creative approver, the technical contact, the note deadline, the included revision process and the delivery date.
- Collect everything into one dated list. Record each change with timecode or section, request, reason, priority, requester and status, as the revision-round guide suggests.
- Resolve conflicts before sending. If one person wants the vocal up and another wants it down, they settle that between them. The engineer should never have to referee.
- One list per round. A remote mixing guide advises avoiding mid-round additions. If you forgot something, treat it as next-round scope.
- Keep the previous file. Don’t delete it until you have checked its replacement.
The Sound article on documentation makes a useful warning: keep brainstorming separate from approvals, or you get “shadow approvals,” where someone likes a change in chat and everyone assumes someone else logged it. For more on running rounds, see our guides to mix revision management and how audio engineers handle revisions.
Final approval: how to document the sign-off
Approval is a record, not a feeling. Before you distribute anything:
- Listen to the actual returned file. Not the preview, not the earlier bounce. Confirm the ending and the version, then record the approval, as the handover guide advises.
- Keep the canonical master and a checksum. For lossless deliverables, store the exact delivered file and a stable checksum as its fingerprint, along with ISRC, UPC and master notes. This distribution guide explains that this lets you tell a correction from an accidental new release.
- Log it. A project management template suggests a master approval log listing file checksums, loudness targets in LUFS and metadata.
- Treat the approved master like a contractual deliverable. Post-approval improvements go through a change request and a budgeted revision round, per the same template.
- Use one naming pattern everywhere. The Sound article recommends project name, deliverable type, version number and date, such as ProjectName_Mix_v07_2026-04-14.wav, applied across sessions, bounces, stems and approvals.
A copy-and-use checklist
Handoff
- [ ] One approved mix per track, stable filename, uncompressed 24-bit
- [ ] Handover sheet with decision maker, references and known issues
- [ ] Destination formats and versions listed
Review
- [ ] Full start-to-finish listen on three or more systems, including mono
- [ ] A/B against the approved mix
- [ ] Every note timestamped and prioritized
Technical
- [ ] Format, sample rate, bit depth, channels and duration match the brief
- [ ] Integrated loudness and true peak measured and in range
- [ ] Fades, edits, sequencing and metadata checked
Sign-off
- [ ] Returned file played in full
- [ ] Approval recorded by the named decision maker, with date and version
- [ ] Master and checksum archived
Our longer mix approval checklist covers the earlier stage, and the audio proofing workflow shows how the pieces fit from first mix to final approval.
Run the whole checklist in one place
A checklist only works if everyone follows it, and clients will not follow a checklist buried in an email thread. Audome is built for this part of the job. You upload lossless audio (up to 96kHz/24-bit), clients leave time-stamped comments on the waveform without needing to log in, and versions are tracked automatically. You can also set revision limits and bill for paid revisions through Stripe.
Plans are published at audome.com/pricing: Studio is $12.50 per month or $150 per year, and Pro is $48 per month or $576 per year. If you want the full picture first, start on the Audome homepage.
If you deliver masters to labels, our guide to delivering final masters and the studio approval process show how to lock files until payment clears. Audio version history explains how to keep every mix and master traceable.
Our perspective
Most approval disputes are not about taste. They are about not knowing which file someone approved, or which note belonged to which version.
We built Audome around that. Feedback should live on the waveform, at the exact moment it applies, so nobody has to translate “it feels harsh somewhere in the middle” into a guess. Versions should track themselves, so the file a client approved is the file you deliver. And the client should not have to create an account to say yes.
We also think approval should have a structure that protects your time. Revision limits and paid revisions turn an open-ended loop into a clear scope, and a branded, password-protected portal makes your process look as professional as your work sounds.
A checklist gives you the steps. A single hub makes people actually follow them.
Kreg
FAQ
What should be on a mastering approval checklist?
Cover four areas: the handoff (approved mix, filename, handover sheet), the listening pass (several systems, start to finish, timestamped notes), the technical pass (format, sample rate, bit depth, loudness, true peak, fades, metadata) and the documentation (approval record, archived file, checksum). The sections above give a copy-ready version.
How many playback systems should I check a master on?
Use at least three: familiar headphones, your usual speakers and a modest system, as Star Sound Studios suggests. Add mono playback and everyday speakers if the music is headed for radio or streaming, since translation problems often show up there first.
How do I handle conflicting feedback from several people?
Name one person with final say, collect all notes into one dated list and have the reviewers resolve disagreements before the engineer sees them. Send one complete list per round, and treat anything forgotten as next-round scope.
What should I keep after the master is approved?
Keep the exact delivered file, a checksum, the loudness figure, the metadata (ISRC, UPC, titles) and a dated record of who approved which version. If you need a correction later, those records show it is a fix and not a new release.
Sources
- Mastering Prep Guide (Cavern of Echoes)
- Master Delivery Checklist for Artists (ASP Recordings)
- Prepare a mixing or mastering handover
- Prepare a Mastering Handoff for Release (IHHR)
- Album Mastering Checklist (Bobby Owsinski)
- From Session to Release: A Production Checklist (Songkeeper)
- After Mastering, What Is the Next Step? (Star Sound Studios)
- Radio Ready Song: Practical Submission Checklist (RBeatz)
- Post-Production Audio Deliverables Checklist (Forte)
- Plan a client revision round
- Clinical Documentation for Audio Projects (The Sound)
- Working with a Remote Mixing Engineer (The Empty Hall Studio)
- Audio Files for Distribution and Post-Release Replacement (Velveteen)
- Step V: Delivery, Generate the Master
- Music Production Project Management Template