Registration restrictions

As you plan your schedule for each quarter, you'll want to make sure that you are qualified to enroll in the courses you select. Learn about possible registration restrictions below. 

Registration periods

Registration periods (sometimes abbreviated "Pd." or "PD" in the Time Schedule) are used to control when certain groups of students can register for certain classes. Period 1 is the time when currently enrolled students register, Period 2 is the time when new students register, and Period 3 is the first week of classes. The dates for these periods each quarter can be found in the Academic Calendar.

Departments use registration periods either to allow declared majors to register for their classes before students outside the major, or to keep students from adding the course after the quarter has begun. If there's a registration period restriction on a class you want to take, make sure you understand it so you can get into the class as soon as you're eligible. The basic rule: restrictions are in effect only for the Period that is noted.

Entry (add) codes

Entry codes are used when there is a requirement for the course that for some reason can't be programmed into the computer, or when the department wants to talk to each student to make sure your background is appropriate for the course. The course details often tells you where to request an entry code. If the information isn't there, contact the department adviser or the instructor.

Entry codes are often required only in certain registration periods. The notation ENTRY CODE PD 3, for example, means that entry codes are required in Period 3, which is the first week of the quarter, but not in Periods 1 and 2 when most registration occurs. After the first week of the quarter, all courses require entry codes. 


Many UW courses have prerequisites. Prerequisites are courses that must be completed before the course in question. Any prerequisites are listed in the Course Descriptions.

Courses requiring prerequisites are indicated with the word "Prerequisites" in the title line in the Time Schedule. When you try to register for a course, the system checks to see if you have completed the prerequisite or have it in progress. If the system can't locate the prerequisite in your record, it won't allow you to register for the course.

Sometimes you may actually have the prerequisite for a course but the system doesn't know it — for example, if you took the prerequisite at another college and the transfer credit hasn't yet been posted, or if the course was posted as "X credit" rather than an equivalent UW course. In such a case, contact the department adviser.


Some courses are designated as "Prerequisite (cancellation in effect)." If you have the prerequisite for such a course in progress when you register, the computer checks at the end of the quarter to make sure you successfully completed the prerequisite. If not, your registration for the course is cancelled and you're notified by email. Courses with cancellation in effect usually require a minimum grade in the prerequisite. This grade is included in the prerequisite statement in the online Course Descriptions.

Repeating a class

Aside from courses that are designed to be repeated (e.g., independent study, research) you may repeat a course only once, with departmental permission. This applies to all courses for which you have received any numerical grade (including 0.0), I, CR/NC, or S/NS.

Consequently, you may find yourself unable to register for a course you’ve taken before. In practice, the departmental permission mentioned above will be a registration period restriction (see below), an entry code restriction (see above), or no restriction at all.

In order to repeat a course again (i.e., take it a third time), you must contact the department adviser for permission.

Credit limits

Until the first day of class (that is, Period 3), you can register for only 19 credits. After that you can add additional credits up to a maximum of 30 credits per quarter.

The UW offers some credit courses on a "self-sustaining" basis, which means that the course is not covered by your regular tuition. You pay a separate fee for the course that covers the entire cost of its instruction. You can take these courses in addition to the regular credit limits (although carrying that many credits might not be recommended). These courses include Online LearningUW Professional & Continuing Education courses, most Academic English Program (AEP) courses (ENGL 102-105), and Early Fall Start.

In any quarter you are taking ENGL 101: Writing from Sources I (10 credits), you may only take a total of 18 credits.

Registration holds

In several situations your registration may be blocked. If you have a registration hold, there is a link from Web Registration where you can find out which office has placed the hold. Below are some of the more common reasons:

105-credit (5 quarter) rule 

You are expected to declare a major by the time you have earned 105 credits and completed 5 quarters. If you have not done so, a hold will be placed on your registration. This hold can be cleared in one of two ways: 1) by declaring your major, or 2) receiving a premajor extension. A premajor extension may be granted by an academic adviser or academic advising office upon a direct request from you. You will likely be granted a premajor extension if it is clear that you have a major in mind and that you are within one or two quarters of being able to declare that major. If the major is capacity-constrained, your plan must also include a non-capacity-constrained alternative major that you are within one or two quarters of being able to declare.

165-credit (11 quarter) rule

Most degree programs will place a hold on your registration when you complete 165 credits and 11 quarters IF you have not filed an application to graduate or made other arrangements with your major department. Make sure you’re in contact with your academic adviser before you get to this point.


All enrolled matriculated students, and all students living in UW residence halls or single-student apartments, are required to provide proof of measles (rubeola) immunity. You are not allowed to register for any classes until Hall Health Primary Care Center confirms that this has been satisfied.


If you owe money to the UW for tuition, late registration fees, etc., your registration will usually be blocked until the situation is resolved.

Return your library materials to remove holds due to library fines.

Some departments will block your registration if you have neglected to return a lab key or other equipment.

Time conflicts

Web Registration will not allow you to register for two courses that meet at the same time or for courses with overlapping meeting times. If you want to add a course that conflicts with another, you must add the second class via email, using the Registration Transaction Form.

  • If the overlap is one hour or less per week, obtain the verbal approval of both instructors. Register for one course online, then register for the second course by emailing the above form to
  • If the overlap is more than one hour per week, you must obtain the signatures or approval emails of both instructors. Register for one course online, then register for the second course by emailing the above form to