Check that you are enrolling in the paid program, not the free account
Signing in to the developer site with an Apple ID and accepting the agreement gives you a free account. That is enough to run your own builds on a device through Xcode, but not to use TestFlight, publish to the App Store, or enable capabilities such as push notifications. Distribution requires the Apple Developer Program, which has its own enrollment, verification and annual fee. A quick test: if you can't create an app record in App Store Connect or a distribution certificate, you are still on the free tier.
The Apple ID you enroll with is hard to swap later
Enrollment attaches to the Apple ID you submit, and that account needs two-factor authentication. Use a dedicated Apple ID on an address the business controls, not a personal account or a mailbox tied to one employee. The Account Holder role is bound to that identity, and changing it later goes through Apple's transfer process rather than a simple email edit. Also check the name, region and phone number on the Apple ID before applying, because later checks compare them with your ID or company records.
For individuals, the legal name must match the ID document
Individual enrollment asks for a legal name and address, and Apple may request a government-issued photo ID or run verification through the Developer app. The usual failure is a name mismatch: reordered names, a missing middle name, script variants or a nickname. The legal name also becomes the seller name shown on the App Store, so confirm you are comfortable with that before submitting. If you entered it wrongly, fix the Apple ID record first or contact developer support instead of resubmitting repeatedly.
For organizations, three records have to line up
Organization enrollment requires a D-U-N-S number, and the legal entity name, address and phone you enter should match the Dun & Bradstreet record. Typical problems are a newly formed company whose D-U-N-S isn't ready, unclear mapping between local-language and English names, and an applicant who lacks authority to bind the company. Apple may phone to confirm the applicant's role, so use a number that gets answered and a company website that loads and belongs to the entity. If the data is wrong, correct the D&B record first, then resubmit.
Payment and status problems: when to wait, when to stop retrying
The fee, currency and renewal behavior are shown on the enrollment page at the time you apply and can differ by region. If payment fails, check that the card allows international online payments, that the billing address matches, and that the Apple ID region fits the country you selected. When status sits in processing, avoid switching cards or creating new accounts, since duplicate submissions can make the record harder to reconcile. A workable rule: wait if nothing changed and no email asked for more information; contact Apple Developer Support once you see a request for documents or the same error twice, with your enrollment ID and a screenshot. Nonprofits, accredited schools and government bodies may qualify for a fee waiver, which is a separate process to start before paying.
After approval, agreements, tax and banking still gate your release
Membership being active doesn't mean you can get paid. Free apps generally only need the latest agreements accepted. Paid apps and in-app purchases require the Paid Applications Agreement, bank details and tax forms under Agreements, Tax and Banking in App Store Connect, handled by the Account Holder or a role with that access. Updated agreements must be re-accepted, and an unaccepted one can block new submissions. Finish this before your first build goes in, and assign roles such as Admin or App Manager to team members rather than sharing the Account Holder login.